DE69823597T2 - Method for monitoring and controlling a high-pressure fuel injection system of a direct-injection internal combustion engine - Google Patents

Description

BACKGROUND THE INVENTION

The The present invention relates generally to a system for diagnosis and the control of a high pressure fuel system for a Engine with fuel injection in the cylinder. Specially concerned the invention a system for the diagnosis of abnormality a high pressure fuel system for a fuel injected engine in the cylinder as well as a control system capable of dealing with the abnormality of the high pressure fuel system for one Engine to handle fuel injection in the cylinder.

traditionally, is an engine with fuel injection in the cylinder known at a fuel is injected directly into a cylinder (a combustion chamber) and the injected fuel is ignited and burnt by means of a spark plug to thereby the fuel consumption, the engine output and the Exhaust emissions too improve.

As in JP-OS 2-169 834 or JP-OS 8-177 699, must at an engine of this type with fuel injection in the cylinder fed to an injector Fuel pressure can be maintained as high pressure to the fuel to inject directly into a cylinder against the cylinder pressure, so that the Fuel from a fuel tank by means of a low-pressure pump (a feed pump) a high-pressure pump is supplied to increase the fuel pressure by means of the high pressure pump and to supply the high pressure fuel to the injector.

there the high-pressure pump does not have sufficient self-priming force for the fuel, so that on the upstream Side of the high-pressure pump, a low-pressure pump, such as an electric Feed pump, is provided so that the fuel from the fuel tank over the Low pressure pump of the high pressure pump can be supplied.

Further has the low pressure pump for uniform supply of the fuel to the High pressure pump has a delivery capacity equal to the or greater than the maximum delivery capacity of the high-pressure pump is, and it is provided a low-pressure regulator for regulating the fuel pressure supplied from the low pressure pump to a predetermined fuel pressure, so that the pressure-regulated fuel fed to the high pressure pump becomes.

Further is in an engine of this type with fuel injection in the cylinder an injection pulse duration for the fuel that defines the fuel injection quantity set the basis of the engine operating condition, and a driver signal, which designates the injection pulse duration is sent to an injector issued so that a desired injection quantity through the injector opening period of the injector based on the injection pulse duration achieved becomes.

Of the Fuel pressure of the high-pressure fuel system for conveying the Fuel from the high pressure pump to the injector must thus be kept at a predetermined fuel pressure. Therefore, will which increased from the high pressure pump Pressure of the fuel to a predetermined controlled fuel pressure regulated by a high pressure regulator, and a high pressure fuel with the controlled fuel pressure is supplied to the injector.

If however, in the high pressure pump or the high pressure regulator, which form the high-pressure fuel system, an error occurs or if Fuel may leak from the high pressure fuel system Fuel pressure of the high pressure fuel supplied to the injector not be kept at the predetermined controlled fuel pressure, So that the Controllability of the fuel injection is worse. If also the Injectors an abnormality such as a faulty opening of the injector may not have a desired amount of fuel injection be obtained so that the Controllability of the fuel injection is worse.

If then the extent of Abnormality of the High pressure fuel system gets bigger, then the controllability of the fuel injection gets worse, so that the Combustion condition of the engine is worse. At one more greatly increasing extent of abnormality The engine may be out of order or damaged.

SUMMARY THE INVENTION

It is therefore an object of the present invention, the above Eliminate problems and a system for diagnosing a high-pressure fuel system for one Specify engine with fuel injection in the cylinder, which is the abnormality a high pressure fuel system of a fuel injection engine accurate in the cylinder can diagnose.

A Another object of the present invention is the specification of a System for controlling an engine with fuel injection in the Cylinder that can make the failsafe when the high pressure fuel system is abnormal.

To fulfill the above and others Objects according to a first aspect of the present invention, a system for the diagnosis of a high-pressure fuel system for an in-cylinder fuel injection engine, wherein the pressure of a fuel is increased by a high-pressure pump to a high-pressure fuel for injecting a high-pressure fuel for the direct injection of the high-pressure fuel into a Cylinder, wherein the diagnostic system comprises (as in the principle block diagram according to 1 (a) shown):
Diagnostic means for monitoring at least one of the behavior of a fuel pressure of a high pressure fuel system and the relationship between an air / fuel ratio and an injection pulse duration for an injector, the diagnostic means determining that the high pressure fuel system is abnormal and information about the abnormality of the high-pressure fuel system when at least one of the conditions that the fuel pressure is abnormal and that the air-fuel ratio is incompatible with the fuel injection pulse is satisfied.

This Diagnosis system monitors at least one of the fuel pressure behavior of the high pressure fuel system of the engine with fuel injection in the cylinder and the relationship between the air / fuel ratio and the fuel injection pulse duration for the injector.

If at least one of the conditions that the behavior of the fuel pressure is abnormal and that the Air / fuel ratio is incompatible with the injection pulse duration, is satisfied, The diagnostic system determines that the High-pressure fuel system is abnormal and provides information about the abnormality of the high pressure fuel system.

at At least one of the behavior of the Fuel pressure of the high-pressure fuel system of the engine with fuel injection in the cylinder and the relationship between the air / fuel ratio and the injection pulse duration for monitors the injector. If at least one of the conditions that the behavior of the fuel pressure is abnormal and that the Air / fuel ratio with If the injection pulse duration is incompatible, it is determined that the high pressure fuel system is abnormal.

If So the high-pressure fuel is abnormal, if, for example, the High pressure pump or the high pressure regulator, which is the high pressure fuel system form, is abnormal, or if fuel leaks from the high-pressure fuel system or if the injector is abnormal, it is possible that abnormality to accurately diagnose the high pressure fuel system.

There Furthermore This diagnostic system provides information about the abnormality of the high-pressure fuel system returns when it is determined that the High-pressure fuel system is abnormal, so it is possible too prevent the Abnormality of the high-pressure fuel system the exhaust emission deteriorates and a harmful one Influence on has the engine.

According to a second aspect of the present invention, there is provided a control system for controlling a cylinder fuel injection engine, wherein a low pressure fuel supplied from a low pressure pump is regulated by a low pressure regulator to a predetermined fuel pressure to be supplied to a high pressure pump, the pressure of the fuel is increased from the high pressure pump and regulated to a predetermined controlled fuel pressure by a high pressure regulator to supply high pressure fuel to an injector, and wherein a fuel injection amount is set based on an engine operating condition and the fuel injection amount is injected from the injector directly into a cylinder wherein the control system comprises (as in the principle block diagram of FIG 1 (b) shown):
an open / close valve device provided in a fuel bypass passage provided to bypass the high pressure regulator to connect between a high pressure fuel system and a low pressure fuel system;
Diagnostic means for monitoring at least one of the fuel pressure behavior of the high pressure fuel system and the relationship between an air / fuel ratio and a fuel injection pulse duration for the injector, the diagnostic means determining that the high pressure fuel system is abnormal if at least one of the conditions that the behavior of the fuel pressure is abnormal and that the air-fuel ratio is incompatible with the injection pulse duration are satisfied;
Open / close valve control means for closing the open / close valve means when the high pressure fuel system is normal and for opening the open / close valve means when the high pressure fuel system is abnormal;
and fuel injection control means for setting an injection pulse duration defining a fuel injection amount for the injector on the basis of the engine operating condition in response to the controlled fuel pressure regulated by the high pressure regulator when the high pressure fuel system is normal, the fuel injection controllers determining the injection pulse duration on the basis of the engine operating condition in response to the pressure of one of Low pressure regulator to provide regulated low pressure fuel when the high pressure fuel system is abnormal.

This Control system monitors at least one of the fuel pressure behavior of the high pressure fuel system of the engine with fuel injection in the cylinder and the relationship between the air / fuel ratio and the injection pulse duration for the Injectors. If at least one of the conditions that behavior the fuel pressure is abnormal and that the air / fuel ratio with the fuel injection pulse duration is incompatible, is satisfied, the control system determines that the high pressure fuel system is abnormal.

If the high pressure fuel system is normal then the open / close valve means, which is provided in the fuel bypass passage to the high pressure regulator to get around the connection between the high-pressure fuel system and the low-pressure fuel system, closed, around the high pressure fuel, its pressure from the high pressure pump elevated and from the high pressure regulator to the predetermined one controlled fuel pressure has been regulated to supply the injector.

there becomes the fuel injection pulse duration which is the fuel injection amount for the Injector defined based on the engine operating condition in dependence from the controlled fuel pressure regulated by the high pressure regulator specified.

If whereas the high pressure fuel system is abnormal, the open / close valve means open, to the low-pressure fuel that has been supplied by the low-pressure pump is to switch from the low pressure regulator to the predetermined Fuel pressure to be regulated, directly to the high-pressure fuel system to feed to supply the low-pressure fuel to the injector. Then, the fuel injection pulse duration becomes the basis of the engine operating condition in response to that of the low pressure regulator regulated pressure of the low pressure fuel specified.

According to this Control system will be at least one of the behavior of the fuel pressure the high-pressure fuel system of the engine with fuel injection in the cylinder and the ratio between the air / fuel ratio and the injection pulse duration for the Injection monitors. If at least one of the conditions that the behavior of the fuel pressure is abnormal and that the Air / fuel ratio is incompatible with the injection pulse duration, is satisfied, it is determined that the High-pressure fuel system is abnormal.

If therefore, the high pressure fuel is abnormal, for example the high pressure pump or the high pressure regulator, which is the high pressure fuel system form, is abnormal, or if fuel leaks from the high-pressure fuel system or if the injector is abnormal, it is possible that abnormality of the high-pressure fuel system to accurately diagnose.

The Diagnostic results for the high pressure fuel system then go into the fuel injection control and when the high pressure fuel system is normal, the open / close valve means, in the fuel bypass passage to bypass the high pressure regulator for the Establishing the connection between the high pressure fuel system and the low-pressure fuel system is provided, closed, so that the High pressure fuel whose pressure is increased by the high pressure pump and by the high pressure regulator on the predetermined controlled Fuel pressure has been regulated, the injector is supplied.

There at this time, the injection pulse duration, the fuel injection amount for the Injector defined based on the engine operating condition in dependence from the controlled by the high-pressure regulator regulated fuel pressure is, so is the pressure of the high pressure fuel supplied to the injector compatible with the injection pulse duration so that a suitable amount of fuel, which corresponds to the required fuel injection amount similar to the injector as with conventional Systems can be injected.

If whereas the high pressure fuel system is abnormal, so is the open / close valve device open, so that the Low pressure fuel supplied by the low pressure pump and from the low pressure regulator to the predetermined fuel pressure regulated is fed directly to the high-pressure fuel system, supplied to the injector to become independent from the high pressure fuel supplied by the high pressure pump and the High pressure regulator, which form the high pressure fuel system is supplied.

Then, the injection pulse duration is set on the basis of the engine operating condition in response to the pressure of the pressure regulated by the low pressure regulator. Thus, the injection pulse duration for the injector is set so that a predetermined fuel injection amount is obtained with the pressure of the low-pressure fuel; and even if there is a fault in the high-pressure fuel system, the injector opening period can be controlled by the injection pulse duration to coincide with the required fuel injection amount, so that it is possible to actually calculate the difference between the required fuel injection amount and that from the injector to exclude injected fuel injection amount, thereby suppressing the deterioration of the controllability of the fuel injection.

There that is, the deterioration of the controllability of the fuel injection can also be prevented when in the high-pressure fuel system there is a mistake, it is possible a damage of the engine by the deterioration of the combustion state of To prevent motor, so that the Engine can continue to operate.

There Further, at this time, the low-pressure fuel from the low-pressure fuel system the high-pressure fuel system is fed, the load the high pressure pump due to the compression of the fuel decreases and the high pressure regulator is out of service. Also So if the high-pressure pump or the high pressure regulator if there is an error, there may be an increase in the degree of abnormality of the high-pressure pump or the high-pressure regulator are prevented, so that a failure, etc. is prevented.

If further than the abnormality of the high-pressure fuel system, a faulty opening of the injection valve occurs in the injector, the low-pressure fuel is the injector fed. Therefore, the load of the injection valve opening against the fuel pressure of the injector, so that the controllability of the fuel injection guaranteed to some extent can be. Also in this case it is possible a deterioration the controllability of the fuel injection to prevent.

If as an abnormality of the high pressure fuel system, an exit of fuel from the High-pressure fuel system occurs is the high-pressure fuel system supplied the low pressure fuel, to reduce the fuel pressure of the high pressure fuel system, so that it is possible an exit of fuel from at least the high pressure fuel system to prevent.

According to a third aspect of the present invention, there is provided a system for controlling an in-cylinder fuel injection engine, wherein a low pressure fuel supplied from a low pressure pump is regulated by a low pressure regulator to a predetermined fuel pressure to be supplied to a high pressure pump, the pressure of the high pressure pump Fuel is increased from the high pressure pump and regulated by a high pressure electromagnetic regulator to supply high pressure fuel to an injector, and wherein a fuel injection timing and a fuel injection amount are predetermined based on an engine operating condition, wherein the fuel injection amount from the injector at the fuel injection timing directly into a cylinder is injected, wherein the control system, as the principle block diagram according to 1 (c) shows,
Diagnostic means for connecting a downstream side of the high pressure electromagnetic regulator to a low pressure fuel system and monitoring at least one of the behavior of fuel pressure of a high pressure fuel system and the relationship between an air / fuel ratio and an injection pulse duration for the injector the diagnostic devices determine that the high pressure fuel system is abnormal when at least one of the conditions is met, the behavior of the fuel pressure is abnormal, and that the air / fuel ratio is incompatible with the injection pulse duration;
High pressure regulator control means for setting a controlled variable for the electromagnetic high pressure regulator so that a predetermined controlled fuel pressure is obtained when the high pressure fuel system is normal, the high pressure regulator controllers providing a controlled variable such that the high pressure electromagnetic regulator is complete is opened when the high-pressure fuel system is abnormal;
and fuel injection control means for setting an injection pulse duration defining a fuel injection amount for the injector on the basis of the engine operating condition in response to the controlled fuel pressure regulated by the high pressure electromagnetic regulator when the high pressure fuel system is normal, the fuel injection controllers Injection pulse duration based on the engine operating condition in response to the pressure of a low pressure fuel regulated by the low pressure regulator when the high pressure fuel system is abnormal.

This control system uses the high-pressure electromagnetic regulator as the high-pressure regulator, and the downstream side of the high-pressure electromagnetic regulator is connected to the low-pressure fuel system. The control system monitors at least one of the ver keeping the fuel pressure of the high-pressure fuel system of the in-cylinder fuel injection engine and the relationship between the air-fuel ratio and the injection pulse duration for the injector.

If at least one of the conditions that the behavior of the fuel pressure is abnormal and that the Air / fuel ratio is incompatible with the injection pulse duration, is satisfied, it is determined that the High-pressure fuel system is abnormal. When the high pressure fuel system is normal is the controlled variable for the electromagnetic high pressure regulator so given that the predetermined controlled fuel pressure is obtained, and the high-pressure fuel whose Increased pressure from the high pressure pump has been ordered by the electromagnetic high-pressure regulator to be regulated to the predetermined controlled fuel pressure is supplied to the injector.

there becomes the injection pulse duration, which is the fuel injection amount for the Injector defined based on the engine operating condition in dependence set by the controlled fuel pressure, that of the electromagnetic High-pressure regulator is regulated.

If On the other hand, the high-pressure fuel system is abnormal, is the high-pressure electromagnetic regulating device fully open, so that the Low pressure fuel supplied by the low pressure pump, from the low pressure regulator to be regulated to the predetermined fuel pressure, the high pressure fuel system fed directly is supplied to the injector to become. Then, the injection pulse duration is based on the Engine operating state depending from the pressure of the regulated by the low-pressure regulator Low pressure fuel specified.

at This control system will be at least one of the behavior the fuel pressure of the high-pressure fuel system of the engine with fuel injection in the cylinder and the relationship between the air / fuel ratio and the injection pulse duration for monitors the injector.

If at least one of the conditions is satisfied that the behavior of the fuel pressure is abnormal is and that that Air / fuel ratio with the injection pulse duration is incompatible, it is determined that the high pressure fuel system is abnormal.

If therefore, the high pressure fuel is abnormal, for example the high pressure pump or the high pressure regulator, which is the high pressure fuel system form, is abnormal, or if fuel is from the high-pressure fuel system outlet or the injector is abnormal, it is possible the abnormality to accurately diagnose the high pressure fuel system.

Also used This control system, the high-pressure electromagnetic regulating device as the high pressure regulator, and the downstream side the high pressure electromagnetic regulator is with the low pressure fuel system connected. The diagnosed results for the high pressure fuel system are reflected in the fuel injection control, and if that High-pressure fuel system is normal, becomes the controlled variable for the high-pressure electromagnetic regulating device so specified, that the predetermined controlled fuel pressure is obtained, and the high-pressure fuel whose Increased pressure from the high pressure pump and from the high pressure electromagnetic regulator to the predetermined one Controlled fuel pressure has been regulated, the injector fed.

there becomes the injection pulse duration, which is the fuel injection amount for the Injector defined based on the engine operating condition in dependence from that of the high pressure electromagnetic regulator regulated controlled fuel pressure given. Therefore, the Pressure of the injector supplied High pressure fuel compatible with the injection pulse duration, so that how at conventional Systems a correct amount of fuel, the required amount of fuel injection corresponds, can be injected from the injector.

If on the other hand, the high pressure fuel system is abnormal the electromagnetic high-pressure regulator completely open, so that the supplied by the low pressure pump Low pressure fuel from the low pressure regulator to the predetermined fuel pressure is to regulate, directly to the high-pressure fuel system for the supply to the Injectors independently is supplied from the high-pressure fuel. Then the injection pulse duration becomes on the basis of the engine operating condition as a function of the pressure of the engine Low pressure fuel regulated by the low pressure regulator specified.

Thus, the injection pulse duration for the injector is set so as to obtain a predetermined fuel injection amount with the pressure of the low-pressure fuel, and even in the event of a malfunction in the high-pressure fuel system, the valve opening period of the injector can be controlled by the injection pulse duration to coincide with the required fuel injection amount agrees, so that it is possible to suppress a difference between the required fuel injection amount and the injection quantity actually injected from the injector, so that deterioration of the controllability of the fuel injection is prevented.

There so a deterioration of the controllability of the fuel injection can also be prevented when in the high pressure fuel system there is a mistake, it is possible a damage of the engine by the deterioration of the combustion state of To prevent motor, so that the Engine can continue to operate.

There Further, at this time, the low-pressure fuel from the low-pressure fuel system the high-pressure fuel system is fed, the load the high pressure pump due to the compression of the fuel decreases and the electromagnetic high-pressure regulator is essentially out of the box Business. Even if therefore in the high-pressure pump or the electromagnetic High-pressure regulator is a fault, it is possible to prevent the extent of abnormality of the high-pressure pump or the high-pressure regulator is larger, so that a strong damage etc. is prevented.

If Furthermore as an abnormality the high-pressure fuel system is experiencing a faulty injection valve opening, the low pressure fuel is supplied to the injector. Consequently can the load of the injection valve opening against the Fuel pressure of the injector can be reduced, so that the controllability the fuel injection guaranteed to some extent can be. Also in this case it is possible a deterioration the controllability of the fuel injection to prevent.

If as an abnormality of the high pressure fuel system, fuel from the high pressure fuel system leakage, the high pressure fuel system becomes the low pressure fuel supplied to reduce the fuel pressure of the high pressure fuel system, so that it possible is, a fuel outlet at least from the high-pressure fuel system to prevent.

There Furthermore the electromagnetic high pressure regulator both the Function of the high-pressure regulating device as well as the function of the open / close valve device according to the second Aspect of the present invention, it is possible to the high pressure regulator and the open / close valve device according to the second Aspect of the present invention. It is therefore possible the Reduce number of parts of the fuel supply system and thereby the construction of the fuel supply system over the Control system according to the second aspect of the present invention to simplify.

According to a fourth aspect of the present invention, the control system may further include: a fuel pressure correction factor table that uses a fuel pressure in a practical use range of the high-pressure fuel system as a parameter to include a fuel pressure correction factor for correcting the change of the fuel injection amount on the basis to store the fuel pressure; and
an abnormal period injection pulse duration table which uses an engine speed and an engine load as parameters to store therein an injection pulse duration adapted to obtain a required fuel injection amount with the low pressure fuel pressure regulated by the low pressure regulator; the normal high-pressure fuel system is normal, the fuel injection controller sets a basic fuel injection amount based on the engine operating condition to specify a basic injection pulse duration used to apply the basic fuel injection amount to one of the high-pressure regulator or the high-pressure electromagnetic high-pressure fuel injection system. Regulator means to obtain predetermined controlled fuel pressure, and which defines a basic valve opening period for the injector on the basis of the basic fuel injection amount, and wherein the fuel injection control means to the fuel driv uck correction factor table on the basis of the fuel pressure of the high-pressure fuel system, to specify a fuel pressure correction factor to correct the basic injection pulse duration by the fuel pressure correction factor to specify a final injection pulse duration for the injector; and wherein, when the high pressure fuel system is abnormal, the fuel injection controllers refer to the abnormal period injection pulse duration table based on the engine speed and the engine load to provide a final injection pulse duration for the injector.

To specify the fuel injection pulse duration, this control system assigns the fuel pressure correction factor table that uses the fuel pressure in the practical use range of the high pressure fuel system as a parameter to store therein a fuel pressure correction factor for correcting the change of the fuel injection amount based on the fuel pressure, and the abnormal period injection pulse duration table which uses the engine speed and the engine load as parameters to set an injection pulse duration therein which is adapted to obtain a required fuel injection amount with the pressure of the low pressure fuel regulated by the low pressure regulator.

If the high-pressure fuel system is normal, becomes the basic fuel injection amount determined on the basis of the engine operating state such that the basic injection pulse duration, by a basic fuel injection amount with one of the high pressure regulator or the high-pressure electromagnetic regulator regulated predetermined to obtain controlled fuel pressure, and the basic valve opening period for the Injector defined based on the basic fuel injection amount and the reference to the fuel pressure correction factor table is based on the fuel pressure of the high pressure fuel system, to specify the fuel pressure correction factor.

By this fuel pressure correction factor becomes the basic injection pulse duration corrected to the final Injection pulse duration for to impose the injector. On the other hand, if the high pressure fuel system is abnormal, the reference to the abnormal period injection pulse duration table is made based on the engine speed and the engine load to the final injection pulse duration for the To impose injections.

As described above, the control system has the fuel pressure correction factor table, the fuel pressure in the practicable use of the High-pressure fuel system as a parameter uses to in it the fuel pressure correction factor for the Correction of change of To store fuel injection amount based on the fuel pressure and the abnormal period injection pulse duration table, which is the Engine speed and the engine load as a parameter uses to in the To save injection pulse duration that is appropriate to the required Fuel injection amount with the pressure of the low pressure regulating unit to obtain regulated low-pressure fuel.

to Specification of the injection pulse duration is when the high pressure fuel system is normal, the basic fuel injection amount based on the engine operating condition given to specify the basic injection pulse duration required to obtain the basic injection amount with one of the high pressure regulator or the high-pressure electromagnetic regulator regulated predetermined controlled fuel pressure is used, and the basic valve opening period for the injector defined on the basis of the basic fuel injection quantity, and the reference to the fuel pressure correction factor table is made based on the fuel pressure of the high pressure fuel system, to specify the fuel pressure correction factor.

Then the basic fuel injection pulse duration is corrected with this fuel pressure correction factor, for the final Injection pulse duration for the To impose injections. Therefore, in addition to the benefits that according to the second or the third aspect of the present invention, the change the actual Fuel injection amount with respect to the required fuel injection amount dependent on from the actual Fuel pressure of the high-pressure fuel system to be corrected, d. H. the actual Fuel pressure that is supplied to the injector to the final injection pulse duration specifying the injector opening period for the injector, because the basic injection pulse duration, the dependent from that of the high-pressure regulator or the electromagnetic High-pressure regulator regulated predetermined controlled Fuel pressure has been specified by the fuel pressure correction factor is corrected when the high-pressure fuel system in which the High-pressure fuel is supplied to the injector, is normal.

Consequently can have a proper injection pulse duration to achieve the required Fuel injection amount is suitable, depending on the pressure of the High-pressure fuel can be specified, which is actually supplied to the injector. As a result, an appropriate amount of fuel may be required Fuel injection quantity corresponds with safety from the injector be injected so that the Control accuracy of the fuel injection further improved can be.

If Further, the high-pressure fuel system for supplying the low-pressure fuel low-pressure fuel system directly to the injector abnormal is, reference is made to the abnormal period injection pulse duration table based on the engine speed and the engine load to the final injection pulse duration for the To impose injections. Therefore, an injection pulse duration, the is appropriate to the required fuel injection amount the pressure of the low pressure fuel regulated by the low pressure regulator to be given exactly.

Thus, even if the high-pressure fuel system for supplying the low-pressure fuel of the low-pressure fuel system directly to the injector is abnormal, the difference between the required injection amount and the fuel injection amount actually injected from the injector can be surely reduced, so that the control availability of fuel injection can be improved.

According to one fifth In the aspect of the present invention, the control system may further include comprising: a fuel pressure correction factor table having a Fuel pressure in a practical range of use of the high pressure fuel system as a parameter to have therein a fuel pressure correction factor to correct the change the fuel injection amount based on the fuel pressure store, with the fuel injection control devices a basic fuel injection amount based on the engine operating condition specify to give a basic injection pulse duration, which is used, the basic fuel injection amount with one of the high pressure regulator or the electromagnetic High-pressure regulator regulated predetermined controlled To obtain fuel pressure, and the one valve opening basic period for the injector defined on the basis of the basic fuel injection quantity, and wherein the fuel injection control means is responsive to the fuel pressure correction factor table based on the fuel pressure of the high pressure fuel system Refer to specify a fuel pressure correction factor wherein the fuel injection control means includes an abnormal period correction factor for the correction specify the basic injection pulse duration as a function of from the pressure regulated by the low pressure regulator of a low pressure fuel when at least the high pressure fuel system is abnormal, and wherein the fuel injection control means the basic injection pulse duration by the fuel pressure correction factor and correct the Abnormal Period Correction Factor to a final injection pulse duration for the To impose injections.

This Control system has the fuel pressure correction factor table on that the fuel pressure in the practicable usage area of the high-pressure fuel system as a parameter to use therein the fuel pressure correction factor for correcting the change the fuel injection amount based on the fuel pressure save.

to Specification of the injection pulse duration becomes the basic fuel injection amount predefined based on the engine operating condition to the basic injection pulse duration to be given to obtain the basic fuel injection amount with that of the high-pressure regulator or the electromagnetic High-pressure regulator regulated predetermined controlled Fuel pressure based on the basic fuel injection amount is used and the basic valve opening period for the injector defined, and the reference to the fuel pressure correction factor table is based on the fuel pressure of the high pressure fuel system, to specify the fuel pressure correction factor.

If furthermore, at least the high pressure fuel system is abnormal the Abnormal Period Correction Factor applied to the basic injection pulse duration dependent on from the pressure of the regulated by the low-pressure regulator To increase low pressure fuel. Then becomes the basic injection pulse duration by the fuel pressure correction factor and corrects the Abnormal Period Correction Factor to the final injection pulse duration for the To impose injections.

As As described above, this control system has the fuel pressure correction factor table on that the fuel pressure in the practicable usage area of the high-pressure fuel system as a parameter to use therein the fuel pressure correction factor for the Correction of change of Store fuel injection amount based on the fuel pressure.

to Specification of the injection pulse duration becomes the basic fuel injection amount predefined based on the engine operating condition to the basic injection pulse duration which is used, the basic fuel injection amount with one of the high pressure regulator or the electromagnetic High-pressure regulator regulated predetermined controlled To obtain fuel pressure, and the basic valve opening period for the Injector defined based on the basic fuel injection amount based on the fuel pressure correction factor table the fuel pressure of the high-pressure fuel system reference is to set the fuel pressure correction factor.

If furthermore, at least the high pressure fuel system is abnormal The Abnormal Period Correction Factor used for the correction to the basic injection pulse duration as a function of the pressure of the from the low pressure regulator to regulated low pressure fuel increase. Then, the basic injection pulse duration becomes by the fuel pressure correction factor and the abnormal period correction factor corrected to the final Injection pulse duration for to impose the injector.

Therefore, when the basic injection pulse duration, which has been set in response to the controlled fuel pressure regulated by the high pressure regulator, is adjusted by the abnormal period correction factor depending on the pressure of the low pressure regulator tion of regulated low-pressure fuel can be corrected so that it is increased, then the injection pulse duration can be easily determined in comparison with the fourth aspect of the present invention in response to the pressure of the low-pressure fuel.

Therefore may be the abnormal period injection pulse duration that in the fourth Aspect of the present invention is omitted, so that it is possible the manhours for the data entry for the one stored in the abnormal period injection pulse duration table Injection pulse duration and the claimed from the table memory to reduce.

There Furthermore The Abnormal Period Correction Factor can be used Specifications of the injection pulse duration during normal and abnormal state of the high-pressure fuel system in some Scope can be shared to simplify control, so that opposite the fourth aspect of the present invention, the manhours required for data entry can be significantly reduced.

According to one Sixth aspect of the present invention may be the control system further comprising: a fuel pressure correction factor table, the pressure regulated by the low pressure regulator a low pressure fuel and a fuel pressure in a workable Usage range of the high-pressure fuel system as a parameter to have therein a fuel pressure correction factor to correct the change the fuel injection amount based on the fuel pressure store, with the fuel injection control devices a basic fuel injection amount based on the engine operating condition specify to give a basic injection pulse duration, which is used, the basic fuel injection amount with one of the high pressure regulator or the electromagnetic High-pressure regulator regulated predetermined controlled To obtain fuel pressure, and the one valve opening basic period for the injector defined on the basis of the basic fuel injection quantity, and wherein the fuel injection control means is responsive to the fuel pressure correction factor table based on the fuel pressure of the high pressure fuel system Refer to specify a fuel pressure correction factor by the basic injection pulse duration to correct the fuel pressure correction factor to a final injection pulse duration for the injector pretend.

This Control system has the fuel pressure correction factor table which regulated the pressure of the low-pressure regulator Low pressure fuel and the fuel pressure in the practicable Usage range of the high-pressure fuel system used as a parameter to therein the fuel pressure correction factor for the correction of the change to store the injection amount based on the fuel pressure.

Around to specify the injection pulse duration becomes the basic fuel injection amount predefined based on the engine operating condition to the basic injection pulse duration which is used, the basic fuel injection amount with that of the high-pressure regulator or the electromagnetic High-pressure regulator regulated to obtain predetermined controlled fuel pressure, and the one Valve opening basic period for the Injector defined based on the basic fuel injection amount and the reference to the fuel pressure correction factor table is based on the fuel pressure of the high pressure fuel system, to specify the fuel pressure correction factor. Then, the basic injection pulse duration becomes corrected by the fuel pressure correction factor to the final injection pulse duration for the To impose injections.

As As described above, this control system has the fuel pressure correction factor table which regulated the pressure of the low-pressure regulator Low pressure fuel and the fuel pressure in the practicable Uses the high-pressure fuel system as a parameter, in it the fuel pressure correction factor for the correction of the change the fuel injection amount based on the fuel pressure save.

Around to specify the injection pulse duration becomes the basic fuel injection amount predefined based on the engine operating condition to the basic injection pulse duration which is used, the basic fuel injection amount with that of the high-pressure regulator or the electromagnetic High-pressure regulator regulated to obtain predetermined controlled fuel pressure, and the one Valve opening basic period for the Injector defined based on the basic fuel injection amount and the reference to the fuel pressure correction factor table is based on the fuel pressure of the high pressure fuel system, to specify the fuel pressure correction factor.

Then, the basic injection pulse duration is corrected by the fuel pressure correction factor to specify the final injection pulse duration for the injector. That is, the fuel pressure range covered by the fuel pressure correction factor table is set to the pressure range of that regulated by the low-pressure regulator Low pressure fuel is extended without being limited to the fuel pressure range in the practical range of use of the high pressure fuel system.

Also so if that regulated by the low-pressure regulator Low pressure fuel is supplied to the injector when the high pressure fuel system is abnormal, the basic injection pulse duration, depending on controlled by the high-pressure regulator regulated Fuel pressure has been specified, be compensated by the fuel pressure correction factor dependent on from the actual Fuel pressure which is supplied to the injector, so that the Injector supplied fuel pressure can be compatible with the injection pulse duration, if the High-pressure fuel-conserving high-pressure fuel system is normal or even when the high pressure fuel system receiving the low pressure fuel is abnormal.

Therefore can the predetermined injection pulse durations during normal and abnormal conditions the high-pressure fuel system are generally used, and the control system can be simpler than that according to the fifth aspect be formed of the present invention.

According to a seventh aspect of the present invention, there is provided a system for controlling an in-cylinder fuel injection engine, wherein a low pressure fuel supplied from a low pressure pump is regulated by a low pressure regulator to a predetermined fuel pressure to be supplied to a high pressure pump. wherein the pressure of the fuel from the high pressure pump is increased and regulated by a high pressure regulator to a predetermined controlled fuel pressure to supply high pressure fuel to an injector, and wherein a low injection late stage lean burn is selected during low engine speeds at low loads based on the operating condition of the engine to specify a fuel injection amount, a fuel injection timing and an ignition timing, which are suitable for the stratified combustion, and during high engine speeds with high L A uniform premixed combustion based on an early injection is selected to provide, based on the engine operating condition, a fuel injection amount, a fuel injection timing, and an ignition timing suitable for uniform premixed combustion, wherein the fuel injection amount from the injector is injected directly into a cylinder to ignite the injected fuel through a spark plug at the ignition timing to achieve the stratified combustion or the uniform premixed combustion, the control system as shown in the principle block diagram in FIG 2 (a) is shown, comprising
an open / close valve device provided in a fuel bypass passage provided to bypass the high pressure regulator to connect between a high pressure fuel system and a low pressure fuel system;
Diagnostic means for monitoring at least one of the fuel pressure behavior of the high pressure fuel system and the relationship between an air / fuel ratio and an injection pulse duration for the injector, the diagnostic means determining that the high pressure fuel system is abnormal if at least one of the conditions are satisfied that the behavior of the fuel pressure is abnormal and that the air-fuel ratio is incompatible with the injection pulse duration;
Open / close valve control means for closing the open / close valve means when the high pressure fuel system is normal and for opening the open / close valve means when the high pressure fuel system is abnormal;
a combustion system selector to select, based on the engine operating condition, the stratified combustion based on the late injection during low-load low engine speeds and the uniform premixed combustion based on the early injection during high-load high engine speeds;
Fuel injection control means for setting an injection pulse duration for the injector, which defines a fuel injection amount suitable for the stratified combustion, based on the operating condition of the engine in response to the controlled fuel pressure regulated by the high-pressure regulator and for setting a fuel injection timing in a compression stroke A cylinder to be injected with when the high pressure fuel system is normal and when stratified combustion is selected, wherein the fuel injection control means determines an injection pulse duration based on the operating condition of the engine based on the controlled fuel pressure regulated by the high pressure regulator specify the injector suitable for the uniform premixed combustion, and a fuel injection timing at the end of an exhaust stroke or a suction stroke of a cylinder, which is to be injected, specify when the high pressure fuel system is normal and when the uniform premixed combustion is selected, and wherein the fuel injection controllers based on the operating condition of the engine in response to that of the low pressure Regulier a regulated pressure of a low-pressure fuel, an injection pulse duration that is suitable for the uniform premixed combustion, and a fuel injection timing that is suitable for the uniform premixed combustion when the high-pressure fuel system is abnormal; and
Ignition timing control means which, based on the engine operating condition, set an ignition timing suitable for the stratified combustion when the high pressure fuel system is normal and stratified combustion is selected, and set an ignition timing for the steady premixed based on the engine operating condition Combustion is suitable when the high pressure fuel system is normal and when uniform premixed combustion is selected or when the high pressure fuel system is abnormal.

This Control system monitors at least one of the behavior of the fuel pressure of the high pressure fuel system and the relationship between the air-fuel ratio and the injection pulse duration for the Injectors. If at least one of the conditions is met, that this Behavior of the fuel pressure is abnormal and that the air / fuel ratio with the injection pulse duration is incompatible, it is determined that the high pressure fuel system is abnormal.

In addition, will based on the engine operating condition during low engine speeds with low loads the stratified combustion on the basis of the late injection selected and while high High speed engine speeds become uniform pre-mixed Combustion based on the early Injection selected.

If The high pressure fuel system is normal, the open / close valve device, the is provided in the fuel bypass passage, the bypass The high pressure pump is provided to the connection between the High-pressure fuel system and the low pressure fuel system, opened to the high pressure fuel whose pressure has been increased by the high pressure pump is to from the high pressure regulator to the predetermined controlled fuel pressure to be fed to the injector.

If the high pressure fuel system is normal and if the stratified combustion chosen is, the injection pulse duration for the injector, which is the Defined fuel injection amount suitable for the stratified combustion is dependent on the engine operating condition controlled by the high-pressure regulator regulated Fuel pressure specified, and the fuel injection timing is in the compression stroke of the cylinder, in the one injection should be done, given.

If the high-pressure fuel system is normal and if the uniform premixed Combustion chosen is the injection pulse duration for the injector, that for the uniform premixed Combustion is suitable and defines the fuel injection quantity, based on the engine operating condition as a function of the High pressure regulator regulated controlled fuel pressure predetermined, and the fuel injection timing is at the end of Exhaust hubs or at the intake stroke of the cylinder, in the injection take place should, given. In addition, will the ignition timing, the for the uniform premixed Combustion is appropriate, given to the uniform premixed To carry out combustion.

If whereas the high pressure fuel system is abnormal, the open / close valve device becomes open, to the low-pressure fuel that is supplied by the low-pressure pump, from the low pressure regulator to the predetermined one Fuel pressure to be regulated, the high-pressure fuel system fed directly, to supply the fuel to the injector. Furthermore, if the high pressure fuel system is abnormal, the injection pulse duration is the same for the premixed Combustion is appropriate, based on the engine operating condition dependent on from the low pressure fuel regulated by the low pressure regulator specified.

there are the fuel injection timing and the ignition timing, the for the uniform premixed Combustion are suitable, based on the engine operating condition given to the uniform premixed Combustion based on the early To carry out injection regardless of the choice of the combustion system.

at At least one of the behavior of the Fuel pressure of the high-pressure fuel system of the engine with fuel injection in the cylinder and the relationship between the air / fuel ratio and the injection pulse duration for monitors the injector. If at least one of the conditions is satisfied that the behavior of the fuel pressure is abnormal and that the Air / fuel ratio is incompatible with the injection pulse duration, it is determined that the high pressure fuel system is abnormal.

So if the high-pressure fuel is abnormal, z. When the high-pressure pump or the high-pressure regulator constituting the high-pressure fuel system is abnormal or when fuel Thus, it is possible to correctly diagnose the abnormality of the high-pressure fuel system from the high-pressure fuel system or when the injector is abnormal.

Further is during low engine speeds with low loads based on the Engine operating conditions the stratified combustion based on the late injection selected and while high engine speeds and high loads is the uniform premixed Combustion based on the early Injection selected.

Then go the diagnosed results for the high-pressure fuel system in the fuel injection control, and when the high-pressure fuel system is normal, the open / close valve device, in the fuel bypass passage to bypass the high pressure pump for the Establishing the connection between the high pressure fuel system and the low pressure fuel system is opened, so that the High pressure fuel whose pressure is increased by the high pressure pump and by the high pressure regulator on the predetermined controlled Fuel pressure has been regulated, the injector is supplied.

If the high pressure fuel system is normal and if the stratified combustion chosen is, the injection pulse duration for the injector, the Defined fuel injection amount suitable for the stratified combustion is dependent on the engine operating condition controlled by the high-pressure regulator regulated Fuel pressure specified.

In addition, will the fuel injection timing in the compression stroke of the cylinder, in which an injection should take place, given, and the ignition, the for the stratified combustion is appropriate is given on the basis of the engine operating condition, to perform the stratified combustion.

It is thus possible the compatibility the pressure of the high pressure fuel supplied to the injector with the injection pulse duration, and when the high-pressure fuel system is normal and the engine operating condition at low engine speeds and low loads, can be a suitable as in conventional systems Amount of fuel to be injected from the injector, which for the stratified combustion is suitable and a predetermined output power in dependence guaranteed by the engine power at this time, so that it is possible the fuel consumption and the exhaust emission through the stratified combustion to improve when the engine is low and low Load is operated.

If Furthermore, the high-pressure fuel system is normal and the uniform premixed combustion chosen is the injection pulse duration for the injector, that for the uniform premixed Combustion is suitable and defines the fuel injection quantity, based on the engine operating condition as a function of the High-pressure regulator regulated regulated pressure preset.

In addition, will the fuel injection timing at the end of the exhaust stroke or in an intake stroke of the cylinder, in which an injection takes place should, given, and the ignition, the for the uniform premixed Combustion is appropriate, given to the uniform premixed To carry out combustion.

It is possible, the compatibility the pressure of the high pressure fuel supplied to the injector with the injection pulse duration, and when the high-pressure fuel system is normal and the engine is operated at high speeds and high load it can be similar as with conventional systems a suitable one of the required fuel injection amount Amount of fuel to be injected from the injector, which for the uniform premixed Combustion is suitable and to obtain a predetermined starting air / fuel ratio dependent on from the engine operating condition at this time.

Then can while high engine speeds with high load a high average effective Pressure by the uniform premixed Combustion to ensure the required engine power, and engine performance can be improved.

If On the other hand, the high pressure fuel system is abnormal, the open / close valve device open, so that the Low pressure fuel that has been supplied by the low pressure pump is to pass through the low pressure regulator on the predetermined Fuel pressure to be regulated directly to the high-pressure fuel system to the feeder is supplied to the injector. Then, when the high-pressure fuel system is abnormal, the Injection pulse duration for the uniform premixed Combustion is appropriate, based on the engine operating condition dependent on from the low pressure fuel regulated by the low pressure regulator specified.

Therefore, the injection pulse duration for the injector is set so that the predetermined fuel injection amount is obtained, which for the uniform premixed combustion with the Pressure of the low-pressure fuel is suitable, and even if there is a fault in the high-pressure fuel system, the injector opening period of the injector can be controlled by the injection pulse duration so that it coincides with the required fuel injection amount, so that the difference between the required fuel injection quantity and from the Injector actually injected fuel injection amount can be reduced to prevent deterioration of the controllability of the fuel injection.

If Further, the high-pressure fuel system is abnormal, the fuel injection timing and the ignition timing, the for the uniform premixed Combustion are suitable, based on the engine operating condition given to the uniform premixed Combustion based on the early To carry out injection regardless of the choice of the combustion system.

If so the high-pressure fuel system is abnormal, even then, when the low-pressure fuel is supplied to the injector, to be injected from the injector, the fuel injection at the end of the exhaust stroke or performed on the intake stroke be, the difference between the pressure of the low pressure fuel and the cylinder pressure is sufficiently ensured, and the fuel injection quantity can through the injector opening period the injector can be precisely measured on the basis of the injection pulse duration, so that it possible is a deterioration of the controllability of the fuel injection with greater certainty to prevent.

Even So if a fault is present in the high-pressure fuel system, it is possible the deterioration to reliably prevent the controllability of the fuel injection and it is possible an engine damage by the deterioration of the combustion state prevent the engine, so that the Engine can continue to operate.

There here as well the low pressure fuel from the low pressure fuel system too the high-pressure fuel system is supplied, the load of the High pressure pump due to the compression of the fuel reduced and the high pressure regulator is out of service. So even if in the high pressure pump or the high pressure regulator a disorder is present, it is possible to prevent that Extent of abnormality the high-pressure pump or the high-pressure regulator becomes larger, so that a big damage etc. is avoided.

If as an abnormality of the high-pressure fuel system a faulty injection valve opening in When the injector occurs, the low pressure fuel becomes the injector fed. Therefore, the injection valve opening load be reduced against the fuel pressure of the injector, so that the Controllability of the fuel injection guaranteed to some extent can be. Also in this case it is possible to prevent the controllability the fuel injection gets worse.

If as an abnormality of the high pressure fuel system, fuel from the high pressure fuel system leak, the low pressure fuel is the high pressure fuel system fed to to reduce the fuel pressure of the high pressure fuel system so that it possible is to at least prevent fuel from the high pressure fuel system exit.

According to an eighth aspect of the present invention, there is provided a system for controlling an in-cylinder fuel injection engine, wherein a low pressure fuel supplied from a low pressure pump is regulated by a low pressure regulator to a predetermined fuel pressure to be supplied to a high pressure pump, wherein the pressure of the fuel from the high pressure pump is increased and regulated by a high pressure electromagnetic regulator to supply a high pressure fuel to an injector, and during low engine speeds at low loads, a late combustion based lean burn is selected to be on the Based on the operating condition of the engine to specify a fuel injection amount, a fuel injection timing and an ignition timing, which are suitable for the stratified combustion, and during high engine speeds with high loads before a uniform before mixed combustion based on an early injection is selected to set, based on the engine operating condition, a fuel injection amount, a fuel injection timing, and an ignition timing suitable for the uniform premixed combustion, wherein the fuel injection amount from the injector is directly injected into a cylinder to ignite the injected fuel through a spark plug at ignition timing to achieve stratified combustion or uniform premixed combustion, the control system as shown in the block diagram in FIG 2 B) shows,
Diagnostic means for connecting a downstream side of the high pressure electromagnetic regulator to a low pressure fuel system and monitoring at least one of the behavior of fuel pressure of a high pressure fuel system and the relationship between an air / fuel ratio and an injection pulse duration for the injector the diagnostic devices determine that the high pressure fuel system is abnormal when at least one of the conditions is satisfied that the behavior of the fuel pressure is abnormal and that the air-fuel ratio is incompatible with the injection pulse duration;
High pressure regulator control means for setting a controlled variable for the high pressure electromagnetic regulator so that a predetermined controlled fuel pressure is obtained when the high pressure fuel system is normal, the high pressure regulator controllers being arranged to set the controlled variable so that the high pressure electromagnetic regulator is fully opened when the high pressure fuel system is abnormal;
Combustion system selectors for selecting, based on the engine operating condition, the stratified combustion based on the late injection during low engine low-speed engine speeds and the uniform premixed combustion based on the early injection during high-load high engine speeds;
Fuel injection control means for setting an injection pulse duration for the injector defining a fuel injection amount suitable for the stratified combustion, based on the engine operating condition in response to the controlled fuel pressure regulated by the high pressure electromagnetic regulator and for setting a fuel injection timing in a compression stroke of a cylinder an injection is to occur when the high-pressure fuel system is normal and when stratified combustion is selected, the fuel injection control means prescribing an injection pulse duration for the injector based on the engine operating condition in response to the controlled fuel pressure regulated by the high-pressure electromagnetic regulator; which is suitable for the uniform premixed combustion, and a fuel injection timing at the end of a Auslaßhubs or at a Ansaugh ub of the cylinder to be injected, when the high pressure fuel system is normal and when the uniform premixed combustion is selected, and the fuel injection controllers based on the engine operating condition depending on the pressure regulated by the low pressure regulator of a low-pressure fuel may specify an injection pulse duration suitable for the uniform premixed combustion and a fuel injection timing suitable for the uniform premixed combustion when the high-pressure fuel system is abnormal; and
Ignition timing control means, which set based on the engine operating condition, an ignition timing suitable for the stratified combustion, when the high-pressure fuel system is normal and when the stratified combustion is selected, and based on the engine operating condition, an ignition timing, which for the uniform premixed combustion is suitable when the high pressure fuel system is normal and when uniform premixed combustion is selected or when the high pressure fuel system is abnormal.

This Control system uses the electromagnetic high-pressure regulator as High-pressure regulating device, and the downstream side of the electromagnetic High pressure regulator is with the low pressure fuel system connected. The control system monitors at least one of the behavior of the fuel pressure of the high pressure fuel system of the engine with fuel injection in the cylinder and the relationship between the air / fuel ratio and the injection pulse duration for the injector.

If at least one of the conditions is satisfied that the behavior of the fuel pressure is abnormal is and that that Air / fuel ratio with the injection pulse duration is incompatible, it is determined that the high pressure fuel system is abnormal. On the basis of the engine operating condition becomes lower during Engine speeds with low loads the stratified combustion chosen on the late Injection based, and the uniform premixed combustion, those on the early injection is based, during high engine speeds with high load selected.

If the high-pressure fuel system is normal, becomes the controlled variable for the high-pressure electromagnetic regulating device so specified, that the predetermined controlled fuel pressure is obtained, and the high-pressure fuel whose Increased pressure from the high pressure pump and from the high pressure electromagnetic regulator to the predetermined one Controlled fuel pressure has been regulated, the injector fed.

If the high pressure fuel system is normal and if the stratified combustion chosen is, the injection pulse duration for the injector, the for the Layer combustion defines appropriate fuel injection quantity, on the basis of the engine operating condition as a function of that of the electromagnetic High pressure regulator regulated controlled fuel pressure given.

In addition, the fuel injection timing is set at the compression stroke of the cylinder to be injected, and the ignition timing suitable for the stratified combustion is based on the engine operation state predetermined so that the stratified combustion is carried out.

If the high-pressure fuel system is normal and if the uniform premixed Combustion chosen is, the injection pulse duration for the injector, the for the uniform premixed Combustion defined appropriate fuel injection quantity on the Base of the engine operating condition as a function of that by the electromagnetic High pressure regulator regulated controlled fuel pressure specified.

In addition, will the fuel injection timing at the end of the exhaust stroke or in an intake stroke of the cylinder, in which an injection takes place should, given, and for the uniform premixed Combustion becomes suitable ignition timing given, so that the uniform premixed Combustion carried out becomes.

If On the other hand, the high-pressure fuel system is abnormal, the high-pressure electromagnetic regulating device fully open, so that the supplied by the low pressure pump Low pressure fuel from the low pressure regulator to the predetermined fuel pressure is to be regulated, is fed directly to the high-pressure fuel system, supplied to the injector to become. If the high-pressure fuel system is abnormal, will the injection pulse duration for the uniform premixed Combustion is appropriate, based on the engine operating condition dependent on from the pressure of the regulated by the low-pressure regulator Low pressure fuel specified.

there are the fuel injection timing and the ignition timing, the for the uniform premixed Combustion are suitable, based on the engine operating condition given, so that the uniform premixed Burning on the early Injection, regardless of the choice of combustion system accomplished becomes.

at This control system is at least one of the behavior the fuel pressure of the high-pressure fuel system of the engine with fuel injection in the cylinder and the relationship between the air / fuel ratio and the injection pulse duration for monitors the injector. If at least one of the conditions is met that the behavior of the fuel pressure is abnormal and that the Air / fuel ratio is incompatible with the injection pulse duration, it is determined that the high pressure fuel system is abnormal.

If So the high-pressure fuel is abnormal, if, for example, the High pressure pump or the high pressure regulator, which is the high pressure fuel system form, is abnormal or if out of the high pressure fuel system Fuel is leaking or if the injector is abnormal it is possible the abnormality of the high-pressure fuel system to accurately diagnose.

Also used the control system is the electromagnetic high-pressure regulator as a high-pressure regulator, and the downstream side the electromagnetic high-pressure regulator is connected to the Low pressure fuel system connected. Further, based on the engine operating conditions while lower Engine speeds with low loads the stratified combustion, the on the late Injection based, chosen, and the uniform premixed combustion, the on the early Injection based will be during high engine speeds with high loads selected.

Then the diagnostic results for the High-pressure fuel system introduced into the fuel injection control, and when the high pressure fuel system is normal, the controlled variable becomes for the high pressure electromagnetic regulation device that the predetermined controlled fuel pressure is obtained, and the high pressure fuel, its pressure increased by the high-pressure pump and by the electromagnetic High-pressure regulator on the predetermined controlled Fuel pressure has been regulated, is supplied to the injector.

If the high pressure fuel system is normal and if the stratified combustion chosen is, the injection pulse duration for the injector, the for the Stratified combustion defines appropriate amount of fuel injection, on the basis of the engine operating condition as a function of that by the electromagnetic High-pressure regulator regulated controlled fuel pressure specified.

In addition, will the fuel injection timing at the compression stroke of the cylinder, in which an injection should take place, given, and the ignition, the for the stratified combustion is suitable will be based on the engine operating condition given, so that the Layer combustion carried out becomes.

It is thus possible to obtain the compatibility of the pressure of the high-pressure fuel supplied to the injector with the injection pulse duration, and when the high-pressure fuel system is normal and the engine operating condition is low during low-speed engine speeds, similar to conventional systems an appropriate amount of fuel is injected from the injector suitable for stratified combustion and having a predetermined output guaranteed performance in response to the engine operating power at this time, so that it is possible to improve the fuel consumption and the exhaust gas emissions by the stratified combustion, when the engine operating condition is present during low engine load with low load.

If Furthermore the high-pressure fuel system is normal and if the uniform premixed Combustion chosen is, the injection pulse duration for the injector, the for the uniform premixed Combustion defined appropriate injection quantity, based on the Engine operating state depending on regulated by the high pressure electromagnetic regulator controlled fuel pressure specified.

In addition, will the fuel injection timing at the end of the exhaust stroke or at the intake stroke of the cylinder, in the injection take place should, given, and for the uniform premixed Combustion becomes suitable ignition timing given, so that the uniform premixed Combustion carried out becomes.

It is therefore possible the compatibility the pressure of the high-pressure fuel supplied to the injector, with the injection pulse duration, and when the high-pressure fuel system is normal and when the engine operating state at high engine speeds with high loads, can be similar as with conventional Systems inject a suitable amount of fuel from the injector, which corresponds to the required injection quantity, that for the uniform premixed Combustion is appropriate and a predetermined output air / fuel ratio in dependence achieved from the engine operating condition at this time.

Then can while high engine speeds with high load a high average effective Pressure by the uniform premixed Combustion are obtained to the required engine output ensure and the engine output can be improved.

If On the other hand, the high-pressure fuel system is abnormal, the high-pressure electromagnetic regulating device fully open, so that the supplied by the low pressure pump Low pressure fuel passing through the low pressure regulator to the predetermined fuel pressure is fed directly to the high-pressure fuel system, supplied to the injector to become independent of the high pressure fuel.

If the high pressure fuel system is abnormal, the injection pulse duration, the for the uniform premixed Combustion is appropriate, based on the engine operating condition dependent on from the pressure of the low pressure fuel regulated by the low pressure regulator specified.

Therefore is the injection pulse duration for set the injector so that the predetermined injection quantity is obtained for the uniform premixed Combustion with the pressure of the low-pressure fuel is suitable, and even if there is a fault in the high pressure fuel system the injection valve opening period of the injector are controlled by the injection pulse duration so that she coincides with the required injection quantity, so that the difference between the required fuel injection amount and the from the Injection actually injected fuel injection quantity can be reduced thereby deteriorating the controllability of the fuel injection to avoid.

If Further, the high-pressure fuel system is abnormal, the fuel injection timing and the ignition timing, the for the uniform premixed Combustion are suitable, based on the engine operating condition given, so that the uniform premixed Combustion based on the early Injection is performed regardless of the choice of the combustion system.

If therefore the high-pressure fuel system is abnormal, even then, when the low pressure fuel is supplied to the injector, to be injected by the injector, the fuel injection at the exhaust stroke end or carried out at the intake stroke be, taking the difference between the pressure of the low-pressure fuel and the cylinder pressure is sufficiently ensured, and the fuel injection amount can through the injector opening period the injector based on the injection pulse duration measured exactly be so that it possible is a deterioration of the controllability of the fuel injection with even greater certainty to prevent.

Also So if there is an error in the high pressure fuel system, Is it possible, the deterioration of the controllability of the fuel injection to prevent with safety, and it is possible to prevent the engine due to the deterioration of the combustion state of the engine damage suffers, so that the Engine can continue to operate.

Further, at this time, since the low-pressure fuel from the low-pressure fuel system is supplied to the high-pressure fuel system, the load of the high-pressure pump due to the compression of the fuel can be reduced, and the High pressure electromagnetic regulator is substantially at rest. Thus, even if there is a fault in the high-pressure pump or the high-pressure electromagnetic regulator, it is possible to prevent the degree of abnormality of the high-pressure pump or the high-pressure regulator from increasing, so that serious damage, etc. can be prevented.

If as an abnormality of the high-pressure fuel system a faulty injection valve opening in When the injector occurs, the injector becomes the low pressure fuel fed. Therefore, the injection valve opening load be reduced against the fuel pressure of the injector, so that the Controllability of the fuel injection guaranteed to some extent can be. Also in this case it is possible a deterioration the controllability of the fuel injection to prevent.

If as an abnormality of the high pressure fuel system, fuel from the high pressure fuel system leakage, the high pressure fuel system becomes the low pressure fuel supplied to reduce the fuel pressure of the high pressure fuel system, so that it possible is, the leakage of fuel from at least the high pressure fuel system to prevent.

There Further, the high pressure electromagnetic regulator both the function of the high-pressure regulator as well as the function of the open / close valve device according to the seventh Aspect of the present invention, it is possible, the high pressure regulator and the open / close valve device according to the seventh Aspect of the invention to be omitted. It is therefore possible the Reduce number of parts of the fuel supply system and the construction of the fuel supply system over the Control system according to the seventh aspect of the present invention to simplify.

According to a ninth aspect of the present invention, the control system may further include: a fuel pressure correction factor table that uses a fuel pressure in a practical use range of the high-pressure fuel system as a parameter to include therein a fuel pressure correction factor for correcting the change of the fuel injection amount on the basis to store the fuel pressure; and
an abnormal-period injection pulse duration table that uses an engine speed and an engine load as parameters to store therein an injection pulse duration that is adapted to obtain a required fuel injection amount for the uniform premixed combustion with the pressure regulated by the low-pressure regulator a low pressure fuel is suitable;
wherein the fuel injection control means predetermines a basic fuel injection amount suitable for the stratified combustion when the high-pressure fuel system is normal and when the stratified combustion is selected, and based on the engine operating condition specifies a basic fuel injection amount based on the engine operating condition is suitable for uniform premixed combustion when the high pressure fuel system is normal and when uniform premixed combustion is selected;
wherein the fuel injection control means sets a basic injection pulse duration used to obtain the basic fuel injection amount with a predetermined controlled fuel pressure regulated by the high-pressure regulator or the high-pressure electromagnetic regulator, and the one basic valve opening period for the injector defines the basis of the basic fuel injection amount, and the fuel injection control devices refer to the fuel pressure correction factor map based on the fuel pressure of the high pressure fuel system to provide a fuel pressure correction factor to correct the basic injection pulse duration by the fuel pressure correction factor to specify a final injection pulse duration for the injector; and
wherein the fuel injection controllers refer to the abnormal period injection pulse duration table based on the engine speed and the engine load to provide a final injection pulse duration for the injector when the high pressure fuel system is abnormal.

Around specify the injection pulse duration, this control system the following: the fuel pressure correction factor table containing the Fuel pressure in the practical range of use of the high pressure fuel system as a parameter to include the fuel pressure correction factor for the correction the change the fuel injection amount based on the fuel pressure save; and the abnormal period injection pulse duration table, which uses the engine speed and the engine load as parameters to to store therein the injection pulse duration, which is suitable to to obtain the required amount of fuel injection, which for the uniform premixed Combustion with the pressure of the regulated by the low-pressure regulator To obtain low pressure fuel.

When the high-pressure fuel system is normal and the stratified combustion is selected, the basic fuel injection amount suitable for the stratified combustion is set based on the engine operating condition. When the high pressure fuel system is normal and when uniform premixed combustion is selected, On the basis of the engine operating condition, the basic fuel injection amount suitable for the uniform premixed combustion is set.

Then becomes the basic injection pulse duration on the basis of the basic fuel injection amount given to obtain the basic fuel injection amount with that of the high-pressure regulator or the electromagnetic High pressure regulator regulated regulated fuel pressure is used and the basic valve opening period for the Injector defined, and the reference to the fuel pressure correction factor table is done on the basis of the fuel pressure of the high pressure fuel system to specify the fuel pressure correction factor.

Then becomes the basic injection pulse duration by the fuel pressure correction factor corrected to the final Injection pulse duration for to impose the injector. On the other hand, if the high pressure fuel system is abnormal, the reference to the abnormal period injection pulse duration table is made based on the engine speed and the engine load to the final injection pulse duration for the To impose injections.

As described above, the control system includes:
the fuel pressure correction factor table that uses the fuel pressure in the practical use range of the high pressure fuel system as a parameter to store therein a fuel pressure correction factor for correcting the change of the fuel injection amount based on the fuel pressure; and
the abnormal period injection pulse duration table which uses the engine speed and the engine load as parameters to store therein an injection pulse duration which is adapted to obtain the required fuel injection amount for the uniform premixed combustion with the pressure regulated by the low pressure regulator the low pressure fuel is suitable.

Around to specify the injection pulse duration when the high pressure fuel system is normal and if the stratified combustion is selected, the basic fuel injection amount, the for the stratified combustion is suitable based on the engine operating condition specified. If the high pressure fuel system is normal and if the uniform premixed Combustion chosen is the basic fuel injection amount, which is for the uniform premixed Combustion is appropriate, based on the engine operating condition specified.

Then becomes the basic injection pulse duration necessary to obtain the basic fuel injection amount by the high-pressure regulator or the electromagnetic High pressure regulator regulated predetermined controlled fuel pressure is used and the basic valve opening period for the injector defined on the basis of the basic fuel injection quantity, and the reference to the fuel pressure correction factor table is done on the basis of the fuel pressure of the high pressure fuel system the fuel pressure correction factor pretend.

Then becomes the basic injection pulse duration by the fuel pressure correction factor corrected to the final Injection pulse duration for to impose the injector. additionally to the advantages associated with the seventh or eighth aspect of the present invention can be obtained, the change the actual Fuel injection amount with respect to the required fuel injection amount dependent on from the actual Fuel pressure of the high pressure fuel system, d. H. the actual Fuel pressure supplied to the injector can be compensated for the final Specify injection pulse duration that the injection valve opening period for the Injectors defined because the basic injection pulse duration, the dependent on from that by the high-pressure regulator or the electromagnetic High-pressure regulator regulated predetermined controlled Fuel pressure has been specified with the fuel pressure correction factor is corrected when the high-pressure fuel system in which the High-pressure fuel is supplied to the injector, is normal.

Therefore can depend on from the pressure of the high-pressure fuel actually supplied to the injector a suitable injection pulse duration to obtain the required Fuel injection amount can be specified. As a result, one can appropriate amount of fuel, the required amount of fuel corresponds to either for the stratified combustion or for the uniform premixed combustion is suitable to be injected from the injector with certainty, So that the Control accuracy of the fuel injection further improved can be.

Further, when the high pressure fuel system for supplying the low pressure fuel of the low pressure fuel system directly to the injector is abnormal, the reference to the abnormal period injection pulse duration table is made based on the engine speed and the engine load to give the final injection pulse duration to the injector. Therefore, an injection pulse duration, which is suitable to obtain the required fuel injection amount, for the uniform premixed combustion with the regulated by the low-pressure regulator pressure of the Low pressure fuel is suitable to be specified exactly.

Also So if the high-pressure fuel system for supplying the low-pressure fuel low-pressure fuel system directly to the injector abnormal is, the difference between the required fuel injection quantity and indeed Injection amount injected from the injector with certainty be reduced, so that the Controllability of the fuel injection can be improved.

According to a tenth aspect of the present invention, the control system may further include:
a fuel pressure correction factor table that uses a fuel pressure in a practical use range of the high pressure fuel system as a parameter to store therein a fuel pressure correction factor for correcting the change of the fuel injection amount based on the fuel pressure;
wherein the fuel injection control means predetermines a basic fuel injection amount suitable for the stratified combustion when the high-pressure fuel system is normal and when the stratified combustion is selected, and based on the engine operating condition specifies a basic fuel injection amount based on the engine operating condition is suitable for the uniform premixed combustion, when the high-pressure fuel system is normal and when the uniform premixed combustion is selected or when the high-pressure fuel system is abnormal, the fuel injection control means predetermining a basic injection pulse duration, which is used, the reason Fuel injection quantity with a predetermined controlled fuel pressure regulated by the high-pressure regulator or the high-pressure electromagnetic regulator, and the basic valve opening period for the injector on the basis the basic fuel injection amount is defined, wherein the fuel injection control means refer to the fuel pressure correction factor table based on the fuel pressure of the high pressure fuel system to set a fuel pressure correction factor;
the fuel injection control means providing an abnormal period correction factor for the correction to increase the basic injection pulse duration in response to the low pressure fuel pressure regulated by the low pressure regulator when at least the high pressure fuel system is abnormal; and
wherein the fuel injection control means corrects the basic injection pulse duration by the fuel pressure correction factor and the abnormal period correction factor to give a final injection pulse duration to the injector.

This Control system has the fuel pressure correction factor table on that the fuel pressure in the practicable usage area of the high-pressure fuel system as a parameter to use therein the fuel pressure correction factor for correcting the change the fuel injection amount based on the fuel pressure save.

Around to specify the injection pulse duration when the high pressure fuel system is normal and when the stratified combustion is selected, that for stratified combustion becomes appropriate basic fuel injection amount based on the engine operating condition given, and if the high-pressure fuel system is normal and if the uniform premixed Combustion chosen or if the high-pressure fuel system is abnormal, the for the uniform premixed Combustion of basic reason fuel injection quantity on the basis the engine operating state specified.

Then becomes the basic injection pulse duration necessary to obtain the basic fuel injection amount by the high-pressure regulator or the electromagnetic High pressure regulator regulated predetermined controlled pressure is used and the basic valve opening period for the injector defined on the basis of the basic fuel injection quantity, and the reference to the fuel pressure correction factor table is based on the fuel pressure of the high pressure fuel system, around the fuel pressure correction factor pretend.

If furthermore, at least the high pressure fuel system is abnormal the abnormal period correction factor for correcting the increase in Basic fuel injection pulse width dependent on from the low pressure fuel regulated by the low pressure regulator specified. Then, the basic injection pulse duration becomes with the fuel pressure correction factor and the abnormal period correction factor corrected to the final Injection pulse duration for to impose the injector.

As As described above, this control system has the fuel pressure correction factor table on that the fuel pressure in the practicable usage area of the high-pressure fuel system as a parameter to use therein a fuel pressure correction factor for correcting the change of Store fuel injection amount based on the fuel pressure.

To specify the injection pulse duration when the stratified combustion is selected, the for the stratified combustion prescribes appropriate basic amount of fuel injection based on the engine operating condition, and if the high pressure fuel system is normal and if the uniform premixed combustion is selected or if the high pressure fuel system is abnormal, the basic fuel injection amount corresponding to the uniform premixed combustion becomes is determined based on the engine operating condition.

Then the basic injection pulse duration associated with obtaining the basic fuel injection amount becomes by the high-pressure regulator or the electromagnetic High pressure regulator regulated predetermined controlled fuel pressure is used and the basic valve opening period for the injector defined on the basis of the basic fuel injection quantity, and the reference to the fuel pressure correction factor table is done on the basis of the fuel pressure of the high pressure fuel system to specify the fuel pressure correction factor.

If furthermore, at least the high pressure fuel system is abnormal the Abnormal Period Correction Factor specified for the correction, around the basic injection pulse duration dependent on from the pressure of the low pressure fuel regulated by the low pressure regulator to increase. Then, the basic injection pulse duration becomes the fuel pressure correction factor and the abnormal period correction factor corrected to the final injection pulse duration for the To impose injections.

Therefore then the basic injection pulse duration, depending on from the controlled fuel pressure regulated by the high pressure regulator with the abnormal period correction factor depending on from the pressure of the regulated by the low-pressure regulator Low pressure fuel can be corrected and increased, so that the injection pulse duration in Comparison with the ninth aspect of the present invention simple way depending on the pressure of the low-pressure fuel can be specified.

Consequently For example, the abnormal-period injection pulse duration employed in the ninth aspect of the invention omitted, so that it possible is the manhour for the data entry for the injection pulse duration included in the Abnormal Period Inject Pulse Duration Table and reduce the amount of memory used by the table.

There Furthermore The Abnormal Period Correction Factor can be used Specifications for the injection pulse duration during the normal and abnormal state of the high pressure fuel system to some extent generally used to control simplify, so that the Manhours for the data input against the Ninth aspect of the present invention can be significantly reduced can.

According to one Eleventh aspect of the present invention may be the control system further comprising: a fuel pressure correction factor table, the pressure regulated by the low pressure regulator a low pressure fuel and a fuel pressure in one practicable use of the high-pressure fuel system as a parameter, to therein a fuel pressure correction factor for the correction of the change To store fuel injection amount based on the fuel pressure the fuel injection controllers being based on of the engine operating condition specify a basic fuel injection amount, the for the stratified combustion is suitable when the high pressure fuel system is normal and if the stratified combustion is chosen, and on the basis of the engine operating condition specify a basic fuel injection amount, the for the uniform premixed Combustion is appropriate when the high pressure fuel system is normal is and if the uniform premixed Combustion chosen or if the high pressure fuel system is abnormal; in which the fuel injection controllers a basic injection pulse duration specify that is used, the basic fuel injection quantity with one of the high pressure regulator or the electromagnetic High-pressure regulator regulated predetermined controlled To obtain fuel pressure, and based on the basic fuel injection amount a valve opening basic period for the Injectors defined, and the fuel injection control devices to the fuel pressure correction factor table based on the fuel pressure of the high pressure fuel system Refer to specify a fuel pressure correction factor by the basic injection pulse duration by the fuel pressure correction factor to correct, to a final Injection pulse duration for to impose the injector.

This Control system has the fuel pressure correction factor table on, which regulated by the low-pressure regulator Low pressure fuel pressure and fuel pressure in one practical range of use of the high-pressure fuel system as Parameter uses to it the fuel pressure correction factor for the correction the change the fuel injection amount based on the fuel pressure save.

To specify the injection pulse duration, if the high pressure fuel system is normal and if stratified combustion is selected, the basic fuel injection amount suitable for stratified combustion is set based on the engine operating condition and if the high pressure fuel system is normal and if uniform premixed combustion is selected or when the high-pressure fuel system is abnormal, the basic fuel injection amount suitable for the uniform premixed combustion is selected on the basis of the engine operating condition.

Then is the basic injection pulse duration used to Basic fuel injection amount with one of the high-pressure regulator or the high pressure electromagnetic regulator to obtain predetermined controlled fuel pressure, and the valve opening basic period for the Injectors defined based on the basic fuel injection amount and the reference to the fuel pressure correction factor table is based on the fuel pressure of the high pressure fuel system, to specify the fuel pressure correction factor. Then the Basic injection pulse duration corrected by the fuel pressure correction factor to the final Injection pulse duration for to impose the injector.

As As described above, this control system has the fuel pressure correction factor table on, which regulated by the low-pressure regulator Low pressure fuel pressure and fuel pressure in the Practical range of use of the high-pressure fuel system as a parameter it uses the fuel pressure correction factor for the correction the change the fuel injection amount based on the fuel pressure save.

Around to specify the injection pulse duration is when the high pressure fuel system is normal and if the stratified combustion is chosen for the stratified combustion appropriate basic fuel injection amount based on the engine operating condition given, and if the high-pressure fuel system is normal and if the uniform premixed Combustion chosen is or if the high pressure fuel system is abnormal, the basic fuel injection amount is premixed for the uniform Combustion is determined based on the engine operating condition.

Then is the basic injection pulse duration used to Basic fuel injection quantity with that of the high-pressure regulator or the electromagnetic High-pressure regulator regulated predetermined controlled To obtain fuel pressure, and the basic valve opening period for the injector defined on the basis of the basic fuel injection quantity, and the reference to the fuel pressure correction factor table is done on the basis of the fuel pressure of the high pressure fuel system to specify the fuel pressure correction factor.

Then becomes the basic injection pulse duration by the fuel pressure correction factor corrected to the final Injection pulse duration for to impose the injector. That is, that of the fuel pressure correction factor table Covered fuel pressure range is limited to the pressure range of Low pressure fuel regulated by the low pressure regulator extended without affecting the fuel pressure range in the practicable Use of the high-pressure fuel system to be limited.

Also so if that regulated by the low-pressure regulator Low pressure fuel is supplied to the injector when the high pressure fuel system is abnormal, the basic injection pulse duration, depending on controlled by the high-pressure regulator regulated Fuel pressure has been specified by the fuel pressure correction factor dependent on from that supplied to the injector actual Fuel pressure can be compensated so that the injection pressure supplied to the injector the injection pulse duration may be compatible when the high pressure fuel system, which receives the high-pressure fuel, is normal, or even if the high-pressure fuel system, the receives the low-pressure fuel, is abnormal.

Therefore can the specifications for the injection pulse duration during normal and abnormal states of the high-pressure fuel system in general use, and the control system may be compared to the tenth aspect of present invention be further simplified.

According to one twelfth Aspect of the present invention may be the fuel injection control devices make an upper limit of the injection pulse duration, the predetermined when the high pressure fuel system is abnormal.

at this control system is to specify the injection pulse duration, if the high pressure fuel system is abnormal, the upper limit the injection pulse duration made so that the engine output power is limited if the high-pressure fuel system is abnormal.

Since in this control system made the upper limit of the injection pulse duration is to limit the engine output in a case where the injection pulse duration is set when the high-pressure fuel system is abnormal, it is possible to increase in addition to the advantages obtained according to the second to eleventh aspect of the present invention to prevent the abnormality of the high-pressure fuel system, and it is possible to prevent the deterioration of the controllability of the fuel injection due to the safety control with certainty to prevent deterioration of the engine combustion state.

According to one Thirteenth aspect of the present invention may be used in the system for diagnosis a high pressure fuel system for a fuel injected engine in the cylinder or the system for controlling an engine with fuel injection In the cylinder the diagnostic equipment determine that the high-pressure fuel system is abnormal if at least one of the conditions is met, that the Fuel pressure of the high-pressure fuel system a predetermined Pressure is not reached even if a predetermined period of time After starting the engine has passed that the fuel pressure of the high-pressure fuel system after starting the engine, not within a normal fuel pressure range is, and that the Injection pulse duration continues, a predetermined value for to exceed a predetermined period of time at a leaner air / fuel ratio.

If in this diagnostic or control system at least one of the Conditions fulfilled is that the Fuel pressure of the high-pressure fuel system a predetermined Pressure is not reached even if the predetermined period of time After starting the engine has passed that the fuel pressure of the high-pressure fuel system after starting the engine, not within the normal fuel pressure range is, and that the Injection pulse duration continues, a predetermined value for to exceed a predetermined period of time at a lean air-fuel ratio, it is determined that the High-pressure fuel system is abnormal.

If, as described above, in this diagnostic or control system at least one of the conditions is satisfied that the fuel pressure of the high-pressure fuel system does not reach a predetermined pressure even if the predetermined Period of time after starting the engine has passed that the fuel pressure of the high pressure fuel system after starting the engine is within the normal fuel pressure range, and that the injection pulse duration continues, one predetermined value for to exceed a predetermined period of time at a lean air-fuel ratio, it is determined that the High-pressure fuel system is abnormal.

In addition to the advantages that according to the first to the twelfth Aspect of the present invention, it is then, when the high pressure fuel is abnormal, e.g. When the high pressure pump, the high pressure regulator and / or the electromagnetic High-pressure regulator, which form the high-pressure fuel system, is abnormal or if fuel from the high-pressure fuel system leakage or if the injector is abnormal, possible, the abnormality of the high-pressure fuel system early to diagnose.

If also the abnormality of the high pressure fuel system due to the compatibility of the air / fuel ratio is determined with the injection pulse duration, so the injection pulse duration determined on the basis of the lean air / fuel ratio. If the Injection pulse duration, which defines the fuel injection quantity, exceeds a predetermined value, which is not usually obtained when the high-pressure fuel system is normal, it is determined that the High pressure is abnormal. It is thus possible the abnormality of the high-pressure fuel system to recognize with certainty.

If furthermore the compatibility the air / fuel ratio is determined with the injection pulse duration, is also the continued Period of the abnormal state of compatibility determined. It is thus possible to have one Misdiagnosis due to the abnormal output value of the air / fuel sensor or the abnormal injection pulse duration based on the response time delay in the Air / fuel ratio feedback correction, the influence of a fault or the like.

SHORT DESCRIPTION THE DRAWINGS

The Drawings show:

1 a basic block diagram of the present invention;

2 a basic block diagram of the present invention (as a continuation of 1 );

3 FIG. 10 is a flowchart of a cylinder determination / engine speed calculation routine in the first preferred embodiment of the present invention; FIG.

4 5 is a flowchart of a high pressure fuel system diagnostic routine in the first preferred embodiment of the present invention invention;

5 FIG. 10 is a flowchart of a bypass selection valve control routine in the first preferred embodiment of the present invention; FIG.

6 a flowchart of a combustion system selecting routine in the first preferred embodiment of the present invention;

7 a flowchart of an ignition control routine in the first preferred embodiment of the present invention;

8th a flowchart of a fuel injection control routine in the first preferred embodiment of the present invention;

9 FIG. 10 is a flowchart of a θ1 crank angle pulse interrupt routine in the first preferred embodiment of the present invention; FIG.

10 FIG. 10 is a flowchart of a θ2-crank angle pulse interrupt routine in the first preferred embodiment of the present invention; FIG.

11 FIG. 5 is a flow chart of an IJST interrupt routine in the first preferred embodiment of the present invention; FIG.

12 a flowchart of a TDWL interrupt routine in the first preferred embodiment of the present invention;

13 a flowchart of a TADV interrupt routine in the first preferred embodiment of the present invention;

14 FIG. 3 is a timing chart showing the relationship between crankshaft pulses, cylinder designation pulses, sparking during stratified combustion, and injector drive signals in the first preferred embodiment of the present invention; FIG.

15 5 is a timing chart showing the relationship between crankshaft pulses, cylinder designation pulses, ignition signals during uniform premixed combustion, and injector drive signals in the first preferred embodiment of the present invention;

16 FIG. 3 is a timing chart showing the relationship between the pressure of a low-pressure fuel and a cylinder pressure in the first preferred embodiment of the present invention; FIG.

17 FIG. 3 is a timing chart showing the behavior of fuel pressure in a high-pressure fuel system in the first preferred embodiment of the present invention; FIG.

18 an explanatory drawing of a range determination value table in the first preferred embodiment of the present invention;

19 a general schematic view of an in-cylinder fuel injection engine in the first preferred embodiment of the present invention;

20 a schematic block diagram of a fuel supply system in the first preferred embodiment of the present invention;

21 a front view of a crank rotor and a crank angle sensor in the first preferred embodiment of the present invention;

22 a front view of a cam rotor and a cylinder determination sensor in the first preferred embodiment of the present invention;

23 a circuit diagram of an electronic control system in the first preferred embodiment of the present invention;

24 a flowchart of a fuel injection control routine in the second preferred embodiment of the present invention;

25 a flowchart of a fuel injection control routine in the third preferred embodiment of the present invention;

26 a general schematic view of an in-cylinder fuel injection engine in the fourth preferred embodiment of the present invention;

27 a circuit diagram of an electronic control system in the fourth preferred embodiment of the present invention; and

28 5 is a flowchart of a high-pressure electronic regulator control routine in the fourth preferred embodiment of the present invention.

DESCRIPTION THE PREFERRED EMBODIMENTS

With reference to the accompanying drawings, the preferred embodiments of the present invention will be below wrote. The 3 to 23 show the first preferred embodiment of the invention.

FIRST EMBODIMENT

With reference to 19 First, the schematic structure of a cylinder fuel injection engine will be described. In 19 designated 1 a in-cylinder four-stroke in-cylinder direct-injection engine (hereafter, simply "engine") for a motor vehicle as an example of an in-cylinder fuel injection engine. This engine 1 is on the right and left row of a cylinder block 1a with cylinder heads 2 Mistake. Every cylinder head 2 is with a suction port 2a and an outlet opening 2 B designed for each cylinder.

In the intake system of this engine 1 stands each intake 2a with an intake manifold 3 in conjunction with a throttle chamber 5 over an air chamber 4 in conjunction, are arranged in the intake ports for the respective cylinders. An air filter 7 is upstream of the throttle chamber 5 via an intake pipe 6 arranged. The air filter 7 is with an air intake chamber 8th in connection.

The throttle chamber 5 is with a throttle 5a equipped with an accelerator pedal 9 interacts. With the intake pipe 6 is a bypass channel 10 to bypass the throttle 5a connected. In the bypass channel 10 is an idle regulating valve (ISC valve) 11 intended. The idling regulating valve 11 is designed so that it is the idle speed of the engine 1 regulated by the fact that the amount of bypass air passing through the bypass channel 10 flows, is regulated on the basis of the valve position during idling.

In the cylinder heads 2 are injectors for each cylinder 13 provided to direct fuel into a combustion chamber (cylinder) 12 inject. For every cylinder of the cylinder heads 2 is a spark plug 13 provided, which has at its front end a discharge electrode leading to the combustion chamber 12 is exposed. The spark plug 13 is via an ignition coil provided for each cylinder 15 with a detonator 16 connected.

As the exhaust system of the engine 1 is an exhaust pipe 18 with an assembly of exhaust manifolds 17 in conjunction with each of the outlet ports 2 B the cylinder heads 2 are connected. A catalyst 19 is in the exhaust pipe 18 provided with a muffler 20 to be connected.

With reference to the 19 and 20 Hereinafter, the structure of a fuel supply system of the engine 1 described. In the 19 and 20 designated 21 a fuel passage for supplying a fuel from a fuel tank 22 to each of the injectors 13 , In the fuel channel 21 Starting from the upstream side, the following components are successively arranged: a fuel filter 23 , an electric supply pump 24 serving as an example of a low pressure pump, a high pressure pump of a motor drive piston pump or the like for increasing the pressure of the feed pump 24 supplied fuel to a predetermined high pressure, a distribution line 26 with each of the injectors 13 communicates and is connected thereto, and a high pressure regulator 27 a well-known mechanical pressure regulator for regulating the injectors 13 supplied fuel to a predetermined controlled fuel pressure (eg PfB = 7 MPa).

A low pressure fuel channel 21a for transporting the fuel from the fuel tank 22 by means of the feed pump 24 is upstream of the high pressure pump 25 in the fuel channel 21 educated. A high pressure fuel channel 21b for increasing the pressure of the low pressure fuel passage 21a supplied fuel to the respective injectors 13 supplying a predetermined high pressure fuel is between the high pressure pump 25 and the high pressure regulator 27 educated.

The low pressure fuel channel 21a downstream of the feed pump 24 is with the fuel tank 22 via a fuel return passage 21c connected. In the fuel return passage 21c is a low-pressure regulator 28 provided as a membrane-type pressure regulator or the like to the fuel pressure in the low-pressure fuel passage 21a to regulate to a predetermined pressure (eg 0.2 MPa).

As a low pressure fuel system, the downstream side is the high pressure regulator 27 with the fuel return passage 21c between the low pressure fuel channel 21a downstream of the feed pump 24 and the low pressure regulator 28 connected. It is thus possible by returning excess fuel from the high pressure regulator 27 to the low pressure fuel channel 21a a feed pump 24 to use with a small capacity.

On the other hand, a fuel bypass passage 21d to bypass the high pressure regulator 27 to establish the connection between the high pressure fuel system and the low pressure fuel system with the high pressure fuel channel 21b between the distribution line 26 and the high pressure regulator 27 connected and connected to it.

The fuel bypass duct 21d is also with the fuel return passage 21c upstream of the low pressure regulator 28 connected and connected. In the fuel bypass channel 21d is a bypass selector valve 29 provided as an electromagnetic selector valve as an example of an open / close valve device.

In a flushing channel 21e for establishing the connection between the high-pressure fuel channel 21b that is between the distribution line 26 and the high pressure regulator 27 is provided, and the fuel return passage 21c , which is downstream of the low pressure regulator 28 is provided, is a fuel evaporation valve 30 an electromagnetic selector valve provided.

sensors etc. for detecting the engine operating condition will be described below described.

An accelerator pedal position sensor 31 a potentiometer or the like is at the support portion of the accelerator pedal 9 provided to the degree of movement (the accelerator pedal position) of the accelerator pedal 9 to detect a required load as an example of an engine load.

A knock sensor 32 is on the cylinder block 1a of the motor 1 attached, and a cooling water temperature sensor 34 is a cooling water pipe 33 facing, with the right and left row of the cylinder block 1a is in communication. A fuel pressure sensor 35 is at the distribution line 26 provided a fuel pressure pf in the high-pressure fuel system that controls the injectors 13 feeds, detect.

Upstream of the catalyst 19 is a linear O ₂ sensor 36 as an example of an air-fuel ratio sensor for detecting an air-fuel ratio. As is well known, the linear O ₂ sensor has 36 a linear output characteristic with respect to an air-fuel ratio, so that it is possible to detect the air-fuel ratio directly on the basis of the output value of the linear O ₂ sensor.

A crank angle sensor 39 as an electromagnetic pickup or the like is arranged so that it is the outer circumference of a crank rotor 38 facing, on a crankshaft 37 of the motor 1 is pivotally mounted. A cylinder determination sensor 42 as an electromagnetic pickup or the like is provided so that it is a cam rotor 41 facing, on a camshaft 40 is provided, which is related to the crankshaft 37 turns by 1/2 turn.

As 21 shows is the crank rotor 38 with projections 38a . 38b and 38c formed on its outer periphery. These projections 38a . 38b and 38c are positioned at crank angles θ1, θ2, and θ3 before the compression top dead center (BTDC) for each cylinder (# 1, # 2, and # 3 cylinders, # 4), where CA is crank angle. In this preferred embodiment, θ1 = 97 ° CA, θ2 = 65 ° CA, and θ3 = 10 ° CA.

As 22 shows is the cam rotor 38 with cylinder determination projections 41a . 41b and 41c provided on its outer periphery. The lead 41a is under a crank angle 84 positioned after top dead center (ATDC) of cylinders # 3 and # 4. The lead 41b has three protrusions, and the first protrusion is positioned at a crank angle ATDC θ5 of the cylinder # 1. The lead 41c has two protrusions, and the first protrusion is positioned at a crank angle ATDC θ6 of the cylinder # 2. In this preferred embodiment, θ4 = 20 ° CA, θ5 = 5 ° CA, and θ6 = 20 ° CA.

Depending on the engine operation, the crank rotates 38 and the cam rotor 41 with the crankshaft 37 and the camshaft 40 , The respective projections 38a . 38b and 38c of the crank rotor 38 are from the crank angle sensor 39 detected. Like the momentum diagrams of the 14 and 15 show, gives the crank angle sensor 39 for every 1/2 rotation of the engine (180 ° CA), crank pulses θ1, θ2, and θ3 (BTDC 97 °, 65 °, 10 ° CA).

On the other hand, the projections of the cam rotor 41 from the cylinder determination sensor 42 between the crank pulses .theta.3 and .theta.1, and a predetermined number of cylinder determination pulses are detected by the cylinder determination sensor 42 output.

As will be described, an electronic control unit calculates 50 (please refer 23 ) an engine speed NE based on an input interval between those of the crank angle sensor 39 output respective crank pulses. The electronic control unit 50 Also, the cylinders, such as a cylinder to be injected with, and a cylinder to be ignited are determined based on a pattern of the work stroke sequence of the respective cylinders (cylinder # 1 → cylinder # 2 → cylinder # 3 → cylinder) # 4 in this preferred embodiment) and on the basis of the values obtained by counting the cylinder determination sensor 42 output cylinder determination pulses are obtained by means of a counter.

The electronic control unit or ECU 50 , in the 23 shown calculates the controlled variables of the injectors 13 , the spark plugs 14 and the ISC valve 11 and performs various control operations of the outputs of control signals, that is, engine control operations such as fuel injection control, ignition timing control and idle speed control, operation control of the supply pump 24 , the open / close control of the bypass selector valve 29 and the open / close control of the fuel evaporation valve 30 ,

The ECU 50 generally comprises a microcomputer in which a CPU 51 , a ROM 52 , a ram 53 , a backup RAM 54 , a counter / clock group 55 and an input / output or I / O interface 56 with each other via bus lines are connected ver. The ECU 50 has integrated therein various peripheral devices, such as a constant voltage circuit 57 for supplying stabilized supply voltages to the respective parts, and a driver circuit 58 as well as an A / D converter 59 that interface with the I / O 56 are connected.

The Counter / timer group is a generic term for different counters, such as free-running counter and a counter to count the entrances cylinder determination sensor signals (cylinder determination pulses), and various timers, such as a fuel injection timer Clock for the ignition, a clock for that Input interval of crank angle sensor signals (crank pulses) and a monitoring counter for monitoring the abnormality of the system. Furthermore become different software counters / clocks used.

The constant voltage circuit 57 is with a battery 61 via a first relay contact of a power supply relay 60 connected, which has two relay contacts of two circuits. The relay winding of the power supply relay 60 is with the battery 61 via an ignition switch 62 connected. The constant voltage circuit 57 is also directly with the battery 61 so that the respective parts of the ECU 50 Energy is supplied when the ignition switch 62 is turned on to the contact of the power supply relay 60 close, and to the security RAM 54 regardless of turning on and off the ignition switch 62 constantly supply reserve energy.

In addition, the battery is with the feed pump 24 via the relay contact of a feed pump relay 63 connected. A second relay contact of the power supply relay 60 is with a supply line for the supply of energy from the battery 61 connected to respective actuators.

The input port of the I / O interface 56 is with the knock sensor 32 , the crank angle sensor 39 , the cylinder determination sensor 42 , a speed sensor 43 for detecting a vehicle speed and a starter switch 44 connected to detect the engine start condition. The input port of the I / O interface 56 is also via the A / D converter 59 with the accelerator pedal sensor 31 , the cooling water temperature sensor 34 , the fuel pressure sensor 35 and the linear O ₂ sensor 36 connected. Also, the input port of the I / O interface 56 a battery voltage VB supplied for monitoring.

On the other hand, the output port is the I / O interface 56 via the driver circuit 58 with the ISC valve 11 , the injectors 13 , the bypass selector valve 29 , the gas evaporation valve 30 a warning light provided on an instrument panel (not shown) 45 connected to the central display of various warning signals and the relay winding of the feed pump relay. The output port of the I / O interface 56 is also with the ignition device 16 connected.

The I / O interface 56 is also with a connector 65 connected for external connection. When a serial monitor (a portable fault diagnosis device) 70 with the connector 65 connected to the external port, the serial monitor 70 the input / output data of the ECU 50 and read disturbance data indicating failures and contents indicative of a high pressure fuel system NG flag FHPNG (to be described later) indicating the abnormality of the high pressure fuel system caused by the self-diagnostic function of the ECU 50 in the security RAM 54 is stored to diagnose the high pressure fuel system. In addition, the serial monitor can 70 perform the initial setting (cancellation) of the fault data.

The diagnosis and initial setting of fault data by the serial monitor 70 is described in detail in our own JP Patent Publication 7-76 730 described.

The CPU 51 processes those from sensor switches via the I / O interface 56 entered detection signals and those via the I / O interface 56 introduced battery voltage corresponding to one in the ROM 52 stored control program and calculates the fuel injection amount, the fuel injection timing, the ignition timing, the duty ratio of a drive signal to the ISC valve 11 based on different data stored in the ROM 53 are stored, different learning value data stored in the safety RAM 54 are stored, and fixed data stored in the ROM 52 are stored to engine control operations, such as the fuel injection control, the ignition timing control and the idle speed control and various control operations, such as the operation control of the supply pump 24 , the open / close control of the bypass selector valve 29 and the open / close control of the fuel evaporation valve 30 perform.

In such a control system, the ECU monitors 50 also the behavior of the fuel pressure Pf in the high-pressure fuel system, that of the fuel pressure sensor 35 is detected, as well as the relationship between that of the linear O ₂ sensor 36 detected air / fuel ratio A / F and the injection pulse duration Ti, the injection valve opening period of the injector 13 Are defined.

When at least one of the conditions is satisfied that the behavior of the fuel pressure Pf is abnormal, and that the air-fuel ratio A / F is incompatible with the injection pulse duration, the ECU determines 50 the abnormality of the high-pressure fuel system to the warning light 45 and report the abnormality of the high pressure fuel system and a high pressure fuel system NG flag FHPNG to a predetermined address of the safety RAM 54 to set, which designates the abnormality of the high-pressure fuel system.

So if the high pressure pump 25 or the high pressure regulator 27 that form the high-pressure fuel system is abnormal, or when fuel leaks from the high-pressure fuel system, the fuel pressure pf of the injectors may increase 13 supplied high-pressure fuel can not be maintained at a predetermined controlled fuel pressure, so that the behavior of the fuel pressure Pf of the high-pressure fuel system is abnormal.

Furthermore, if the injectors 13 Due to a faulty injection valve opening or the like are abnormal, it is not possible to obtain a desired fuel injection amount, so that the air / fuel ratio A / F with the injection pulse duration Ti, which injector opening period of the injectors 13 defined, incompatible.

It is therefore possible to accurately diagnose the abnormality of the high-pressure fuel system by the behavior of the fuel pressure Pf of the high-pressure fuel system and the relationship between the air-fuel ratio A / F and the injection pulse duration Ti, the injector opening period of the injectors 13 defined, determined.

When doing the diagnosis of the high-pressure fuel system, the ECU determines 50 the abnormality of the high-pressure fuel system when at least one of the conditions is satisfied that the fuel pressure Pf of the high-pressure fuel system does not reach a predetermined pressure even if a predetermined time has elapsed after starting the engine that the fuel pressure Pf of the high pressure Fuel system is not within the normal fuel pressure range after the engine has been started, and that the injection pulse duration Ti continues to exceed a predetermined value during a predetermined period of lean air / fuel ratio.

In addition, the diagnostic results of the high-pressure fuel system are input to the fuel injection controller to execute fail-safe control. That is, when the high pressure fuel system is normal, the bypass selector valve is 29 closed to prevent fuel from the fuel bypass passage 21d leaks to the injectors 13 to supply a high pressure fuel whose pressure from the high pressure pump 25 is increased by the high-pressure regulator 27 to be regulated to a predetermined controlled fuel pressure.

When doing the injection pulse duration Ti, which is the fuel injection quantity for the injectors 13 defined based on the engine operating conditions as a function of that by the high pressure regulator 27 predetermined controlled fuel pressure PfB is given, it is possible, similar to conventional systems to obtain a fuel injection amount corresponding to a required injection quantity.

On the other hand, when the high pressure fuel system is abnormal, the bypass selector valve becomes 29 opened to the connection between the high-pressure fuel system and the low-pressure fuel system through the fuel bypass passage 21d to be made by the feed pump 24 supplied low-pressure fuel passing through the low-pressure regulator 28 is to be regulated to a predetermined fuel pressure is supplied to the high-pressure fuel system directly to the injectors 13 to be fed.

Then, the injection pulse duration Ti, which is the fuel injection amount for the injectors 13 defines, based on the engine operating conditions in response to the pressure of the low pressure fuel, its pressure through the low pressure regulator 28 is regulated, given.

If, therefore, as a result of the abnormality of high pressure pump 25 or the high pressure regulator 27 that form the high-pressure fuel system, or due to the leakage of fuel from the high-pressure fuel system or when the fuel pressure Pf of the high-pressure fuel system due to the abnormality of the high-pressure regulator 27 is abnormally increased, the pressure of the high pressure fuel of the high pressure fuel system does not reach the predetermined controlled fuel pressure PfB, the bypass select valve becomes 29 closed to supply the low-pressure fuel of the low-pressure fuel system directly to the high-pressure fuel system to the fuel to the injectors 13 regardless of the high pressure fuel from the high pressure pump 25 and the high pressure regulator 27 ,

Since the injection pulse duration Ti for the injectors 13 is predetermined so that a predetermined amount of fuel injection is obtained under the pressure of the low-pressure fuel, even if the abnormality of the high-pressure fuel system occurs, the injector opening period of the injectors 13 are controlled by the injection pulse duration Ti so that it coincides with a required injection quantity, so that the difference between the from the injectors 13 actually injected fuel injection amount and the required injection amount can be reduced, thereby to prevent the deterioration of the controllability of the fuel injection.

There that is, the deterioration of the controllability of the fuel injection even if the abnormality of the high pressure fuel system is inhibited occurs, it is possible a damage of the engine due to the deterioration of the combustion state in To prevent engine and continue to operate the engine.

Further, at this time, the low-pressure fuel is supplied from the low-pressure fuel system to the high-pressure fuel system, so that the load of the high-pressure pump 25 due to the compression of the fuel is reduced, and the high-pressure regulator 27 is in ineffective condition. Even if, for example, the high-pressure pump 25 or the high pressure regulator 27 is abnormal, an increase in the degree of abnormality can be suppressed to prevent severe damage to the engine.

In addition, if a faulty injection valve opening in the injectors 13 As the abnormality of the high-pressure fuel system occurs, the injectors become 13 the low pressure fuel is supplied so that the opening load of the injector against the fuel pressure of the injectors 13 is reduced. It is therefore possible to ensure the controllability of the fuel injection to a certain extent, so that it is also possible to suppress deterioration in the controllability of the fuel injection in this case.

If also the abnormality it is that fuel exiting the high pressure fuel system, the low pressure fuel is supplied to the high pressure fuel system to reduce the fuel pressure of the high pressure fuel system so that it possible is, the leakage of fuel from at least the high pressure fuel system to prevent.

In particular, in this preferred embodiment, the ECU diagnoses 50 the abnormality of the high-pressure fuel system. Based on the engine operating condition, the ECU selects 50 stratified combustion based on the late injection during low engine speeds at low loads, and chooses the uniform premixed combustion based on the early injection during high engine speeds at high loads.

If the high pressure fuel system is normal, the bypass selector valve is 29 closed to supply high pressure fuel to the injector, its pressure from the high pressure pump 25 was increased to be regulated by the high-pressure regulator to a predetermined controlled pressure.

When the high-pressure fuel system is normal and the stratified combustion is selected, the injection pulse width Ti becomes the fuel injection quantity for the injectors suitable for the stratified combustion 13 defined on the basis of the engine operating conditions so as to be with that by the high pressure regulator 27 defined fuel pressure controlled PfB, and the fuel injection timing is in the compression stroke of a cylinder, in which the injection is to be made, given.

Further will the for the stratified combustion suitable ignition timing on the basis of Motor operating state specified. During low engine speeds At low loads, therefore, the stratified combustion is carried out to the exhaust emission and to improve fuel consumption.

Further, when the high-pressure fuel system is normal and when the uniform premixed combustion is selected, the injection pulse width Ti becomes the fuel injection quantity for the injectors suitable for the uniform premixed combustion 13 defined on the basis of the engine operating state, that they are with by the high pressure regulator 27 defined fuel injection pressure PfB and the fuel injection timing is given at the end of the exhaust stroke or in the intake stroke for a cylinder into which injection is to take place.

In addition, will the for the uniform premixed Combustion suitable ignition timing predefined on the basis of the engine operating state. While high High speed engine speeds thus become the uniform premixed one Combustion carried out, to improve engine performance.

On the other hand, if the high-pressure fuel system is abnormal, the bypass selector valve becomes 29 opened so that the low pressure fuel of the low pressure fuel system is fed directly to the high pressure fuel system to the injectors 13 to be fed. Then, when the high-pressure fuel system is abnormal, the injection pulse width Ti suitable for the uniform premixed combustion is set based on the engine operating condition so as to match the pressure of the low-pressure fuel supplied by the low-pressure regulator 28 is regulated.

If while the fuel injection timing and the ignition timing for the uniform premixed Combustion are suitable, based on the engine operating condition are given, the uniform premixed combustion, the on the early Injection based, carried out regardless of the chosen combustion system.

When the high-pressure fuel system is abnormal and when the fuel injection timing at the compression stroke is set to coincide with the stratified combustion, as in FIG 16 is shown, the low-pressure fuel of the low-pressure fuel system to the injectors 13 feed the low pressure fuel into the cylinder (into the combustion chamber 12 ), it is not possible to measure the pressure difference between the pressure of the injector 13 to ensure sufficient injection of low-pressure fuel and the cylinder pressure, and it is not possible, the fuel injection amount through the injector opening timing of the injector 13 to accurately measure Ti on the basis of the injection pulse duration, so that the controllability of the fuel injection is deteriorated.

Therefore, at this time, the fuel injection amount by the injector opening period of the injector 13 based on the injection pulse duration Ti are accurately measured by performing the uniform premixed combustion, wherein the fuel injection timing at the end of the exhaust stroke or the intake stroke is predetermined, the pressure difference between the pressure of the low pressure fuel and the cylinder pressure is sufficiently ensured.

That is, the ECU 50 may perform the respective functions of diagnostic devices, open / close valve controllers, fuel injection controllers, combustion system selectors, and ignition timing controllers according to the present invention.

With reference to the flowcharts of 3 to 13 a control procedure is described by the ECU 50 is carried out according to the present invention.

First, the ignition switch 62 switched on. If the ECU 50 Power is supplied, then the system is initialized and the respective flags and counters are initialized except for data such as various learned values stored in the safety RAM 54 are stored.

If the system initialization of the ECU 50 is executed, the ECU gives 50 a drive signal to the fuel evaporation valve 30 to the fuel evaporation valve 30 open so that the high-pressure fuel channel 21b between the distribution line 26 and the high pressure regulator 27 with the fuel return passage 21c downstream of the low pressure regulator 28 over the flushing channel 21e is connected. In addition, the feed pump relay becomes 63 activated to the feed pump 24 to activate and operate the feed pump 24 to start.

Therefore, the fuel in the fuel tank 22 the feed pump 24 through the filter 23 fed.

Furthermore, if the system initialization of the ECU 50 is executed, the bypass selector valve 29 closed to the connection between the low pressure fuel system and the high pressure fuel system through the fuel bypass passage 21d to lock. Further, after the system initialization, the bypass selector valve becomes 29 opened and closed depending on the diagnostic results of the abnormality of the high-pressure fuel system from the base of an in 5 shown bypass selector valve control routine which will be described.

The one from the feed pump 24 fuel is supplied by the low-pressure regulator 28 Regulated to the high pressure pump 25 to be fed and excess fuel is from the low pressure regulator 28 to the fuel tank 22 through the fuel return line 21c recycled.

At this time is the engine 1 not yet started, and the high pressure pump 25 is stopped. The high pressure pump 25 has the motor drive piston pump or the like as described above, and each of its inlet and outlet ports has a check valve (not shown) through which the fuel via the high-pressure pump 25 in the high-pressure fuel channel 21b flows.

If the fuel evaporation valve 30 is open, so that the high-pressure fuel channel 21b between the distribution line 26 and the high pressure regulator 27 with the fuel return channel 21c downstream of the low pressure regulator 28 over the flushing channel 21e is connected, the fuel from the high-pressure fuel passage 21b through the flushing channel 21e and the fuel return passage 21c to the fuel tank 22 returned.

Thus, even if gas is generated in the fuel supply system, the gas in the fuel tank 22 issued. It is thus possible to prevent the deterioration of the controllability of the fuel injection due to the gas and to start the engine 1 to be ready.

If then the starter switch 44 is turned on to the engine 1 to start, the ECU closes 50 the fuel evaporation valve 30 in response to turning on the starter switch 44 and then blocks the connection between the high pressure fuel system and the fuel tank 22 through the flushing channel 21e ,

Then the high pressure pump 25 by starting the engine 1 powered to that of the feed pump 24 pressurized fuel and the fuel evaporation valve 30 is opened so that the high pressure regulator 27 can regulate the pressure of the fuel, so that through the high-pressure regulator 27 regulated predetermined high pressure fuel to the injector 13 for each cylinder through the manifold 26 is supplied.

When the starter switch 44 is turned on to the engine 1 In addition, an in 3 shown cylinder determination / engine speed calculation routine executed each time, if from the crank angle sensor 39 a crank pulse is input.

In this cylinder determination / engine speed calculation routine, when the crank rotor becomes 39 rotated in response to the engine operation to a crank pulse from the crank angle sensor 39 input first based on the input pattern of the cylinder determination pulse from the cylinder determination sensor 42 In step S1, it is determined which crank angle θ1, θ2 or θ3 corresponds to the currently input crank pulse.

Then in step S2, the determination of a cylinder, such as a cylinder, to be detonated should, and a cylinder into which an injection is to take place, on the basis of the input pattern of the crank pulse and the cylinder determination pulse and on the basis of the working stroke sequence of the respective cylinders (Cylinder # 1 → Cylinder # 3 → Cylinder # 2 → cylinder # 4 in this preferred embodiment) carried out.

If, like the momentum diagrams of the 14 and 15 For example, if a cylinder determination pulse is input before the current crank pulse is input after the last crank pulse input, it can be determined that the current crank pulse is a crank pulse &thetas; 1 and the next input crank pulse is a crank pulse &thetas; 2.

If Furthermore between the last and the momentary input of crank pulses no cylinder determination pulse is input and if between the crank pulse that was entered before the last, and the Last entered crank pulse input a cylinder determination pulse can be determined that the current Crank pulse of the crank pulse θ2 is and the next input crank pulse is a crank pulse θ3.

If between the last and the momentary input of crank pulses and between the before the last entered crank pulse and the last input crank pulse no cylinder determination pulse is input, it may be determined that the currently input crank pulse the crank pulse θ3 is and the next entered Crank pulse of the crank pulse θ1 is.

Further, when between the input of the last and the present crank pulses, three cylinder determination pulses (a cylinder determination pulse θ5 corresponding to the projection 41b ), the # 3 cylinder is positioned at a crank angle of the next upper compression dead center, and it can be determined that the cylinder to be fired of the # 3 cylinder is.

14 shows a pulse diagram during the stratified combustion, and 15 shows a pulse diagram during the uniform premixed combustion. In the stratified combustion according to 14 it is necessary to use the fuel to perform injection into a respective cylinder in a compression stroke and to stop the fuel injection immediately before ignition.

At the in 15 shown uniform premixed combustion, it is possible to carry out the fuel injection into a respective cylinder at the end of a Auslaßhubs or during the intake stroke, because the ignition takes place after the injected fuel in the combustion chamber (in the cylinder) 12 is sufficiently distributed to be evenly mixed with air.

There in this preferred embodiment the Fuel injection for the respective cylinder in a maximum position of BTDC 380 ° CA of the corresponding Cylinders while the uniform premixed Combustion begins, it is necessary to put a cylinder in the one Injection is to be identified before the BTDC 380 ° CA position. Therefore, a cylinder #i to inject into, determined on the basis of the cylinder determination results when the Crank pulse θ2 entered at a position of BTDC 425 ° CA for the corresponding Cylinder is entered, and based on the working stroke sequence the respective cylinder (cylinder # 1 → cylinder # 3 → cylinder # 2 → cylinder # 4 in this preferred embodiment) certainly.

Thus, if the currently determined cylinder (a cylinder in a position of the next upper compression dead center) of the cylinder is # 3 when the crank pulse θ2 is input, it is determined that the cylinder # 2 is the cylinder #i to which injection is to be made when the stratified combustion is selected (see 14 ), and that the cylinder # 4 is a cylinder #i into which injection is to be made when the uniform premixed combustion is selected (see 15 ).

On the other hand, when two cylinder determination pulses (cylinder determination pulses θ6 corresponding to the projection 41c ) between the last and the current input of crank pulses, the cylinder # 4 is positioned at the next upper compression dead center, so that it can be determined that the cylinder to be fired is the cylinder # 4.

If the specific cylinder of the # 4 cylinder is when the cranking pulse θ2 is input it is determined that the Cylinder # 1 the next Cylinder #i is where an injection should take place when the Layer combustion selected is, and that the Cylinder # 3 the next Cylinder #i is where an injection should take place when the uniform premixed Combustion chosen is.

Further, when a cylinder determination pulse (a crank pulse θ4 corresponding to the projection 41a is entered between the last and the current input of crank pulses, and when the last specific cylinder is in a position of the compression top dead center of the # 4 cylinders, it can be determined that the # 1 cylinder is positioned at the next upper compression dead center and the cylinder # 1 is the cylinder #i into which an injection is to be made.

If the particular cylinder is the cylinder # 1 when the crank pulse θ2 is input it is determined that the Cylinder # 3 the next Cylinder #i is where an injection should take place when the Layer combustion selected is, and that the Cylinder # 2 the next Cylinder #i is where an injection should take place when the uniform premixed Combustion chosen is.

If a cylinder determination pulse between the last and the current one Input of crank pulses is entered and if the last specific Cylinder in a position of the upper compression dead center Cylinder # 3 is alike cylinder # 2 at the next positioned top compression dead center, so that it can be determined that to brilliant Cylinder is the cylinder # 2.

If the particular cylinder is the cylinder # 2 when the crank pulse θ2 is input it is determined that the Cylinder # 4 the next Cylinder #i is where an injection should take place when the Layer combustion selected is, and that the Cylinder # 1 the next Cylinder #i is where an injection should take place when the uniform premixed Combustion chosen is.

After that the routine goes to step S3 in which a period of time between the last and current input of crank pulses, d. H. a crank pulse input interval (an input interval Tθ12 between the θ1 crank pulse and the θ2-crank pulse, an input interval Tθ23 between the crank pulse θ2 and the crank pulse θ3, or an input interval Tθ31 between the crank pulse θ3 and the crank pulse θ1), that from a clock for the clock of the crank pulse input interval is clocked, read out and a crank pulse input interval Tθ is detected.

Then, the routine goes to step S4 in which an angle between crank pulses corresponding to the currently determined crank pulse is read out, and an engine speed NE is calculated on the basis of the angle between crank pulses and the crank pulse input interval Tθ to be stored in the RAM 53 to be stored at a predetermined address. Then the routine ends.

It is known that the angles between crank pulses previously exist as fixed data in the ROM 52 get saved. In this preferred embodiment, the angle θ12 between the crank pulse θ1 and the crank pulse θ2 is 32 ° CA, the angle θ23 between the crank pulse θ2 and the crank pulse θ3 is 55 ° CA, and the angle θ31 between the crank pulse θ3 and the crank pulse θ1 is 93 ° CA.

After system initialization is completed, an in 4 The high pressure fuel system diagnostic routine shown has been executed every predetermined period (eg, every 10 ms) to perform the high pressure fuel system failure diagnosis. Then, in a bypass selector valve control routine that is in 5 is shown and executed every predetermined period, depending on the diagnostic results for the high-pressure fuel system, the bypass selector valve 29 closed when the high pressure fuel system is normal and open when the high pressure fuel system is abnormal.

Further, in a combustion system selecting routine according to FIG 6 the engine speed NE is read, which is to be used for the selection of a combustion system. Then, in an ignition control routine according to 7 and a fuel injection control routine according to 8th the engine speed NE, the diagnostic results for the high pressure fuel system, and the selected results for the combustion system are read to be used to determine the combustion system and to set the ignition timing, the injection pulse duration, and the fuel injection timing.

Hereinafter, the high-pressure fuel system diagnostic routine will be explained 4 described. First, in step S11, a stall determination is performed by means of the engine speed NE.

If in this preferred embodiment at least one of the following conditions is met: (1) that the Fuel pressure Pf of the high-pressure fuel system even after expiration a predetermined period of time after the engine is started (2) that the fuel pressure Pf of the High pressure fuel system not within the normal range is the fuel pressure after starting the engine, and (3) that the injection pulse duration Ti continuously, a predetermined value for a predetermined period of time in lean air / fuel ratio, it is determined that this High-pressure fuel system is abnormal. In addition, if all conditions (1) to (3) fulfilled it is determined that the High pressure fuel system is normal.

at NE = 0, d. H. if a stall occurs, the high-pressure pump is not in operation, and the fuel injection will not be performed, so that it not possible is, the abnormality to diagnose the high-pressure fuel system. In this case Thus, the routine goes from step S11 to step S12, without the High-pressure fuel system to diagnose.

In steps S12 to S15, an initial diagnostic end flag FAS set at the end of the abnormality diagnosis of the high pressure system due to the behavior of the fuel pressure immediately after engine startup, ie, the initial diagnosis, is a start switch ON determination end flag FINI is set when the start switch 44 is turned on, a time count CAS after starting the engine for counting the time after starting the engine on the basis of turning on the start switch 44 , and an initial diagnosis OK flag FOK which is set when it is determined by the initial diagnosis immediately after starting the engine that the high-pressure fuel system is normal, respectively reset (FAS ← 0, FINI ← 0, CAS ← 0, FOK ← 0).

Then At step S16, a continuation abnormality time count CNG for clock control the continued duration, in which the injection pulse duration Ti continues, a exceed predetermined value at lean air / fuel ratio, reset (CNG ← 0), and the routine ends up for to be prepared to diagnose the fault of the high pressure fuel system which is executed after starting the engine.

If on the other hand, it is determined in step S11 that NE ≠ 0, the routine goes to step S17 in which, based on the reference to the initial diagnostic end flag FAS determines if the initial diagnosis is based on the behavior the fuel pressure Pf of the high-pressure fuel system immediately after starting the engine is completed.

at FAS = 0, d. H. if the initial diagnosis after starting the engine is not completed, the routine goes to step S18. In Steps S18 to S26 become the abnormality of the high-pressure fuel system diagnosed by the condition (1) described above Compare the fuel pressure Pf of the high pressure fuel system in a predetermined period of time after starting the engine with a predetermined value.

In step S18, reference is made to the start switch ON determination end flag FINI. At FINI = 0, ie when switching on the start switch 44 has not yet been determined, the routine goes to step S19, where it is determined whether the starting switch 44 has been turned on.

When the start switch 44 OFF, ie at NE ≠ 0 and FINI = 0, and when the start switch 44 has not yet been turned on, although the engine speed has been detected for the first time, there is no compatibility, so that the routine goes to step S12. After the steps S12 to S16, the routine ends.

On the other hand, when it is determined in step S19 that the start switch 44 Is ON, the start switch ON determination end flag FINI is set in step S20 (FINI ← 1), and the routine goes to step S21. If the start switch ON determination end flag FINI is set, if the next and subsequent routines are executed until the initial diagnosis for the high pressure fuel system ends, the routine goes to step S18 through steps S11 and S17, and then jumps Routine from step S18 to step S21.

In step S21, the time count CAS becomes after starting the engine for timing the duration after starting the engine on the basis of turning on the start switch 44 counted up (CAS ← CAS + 1). Subsequently, in step S22, the time count CAS after starting the engine is compared with a predetermined value CS1 to determine whether the period of time after starting the engine reaches a predetermined time.

The predetermined value CS1 is previously derived by the following simulation or experimentally. The high pressure fuel pump 25 is due to the operation of the engine 1 powered after starting the engine when the high-pressure fuel system is normal. The time until the fuel pressure Pf of the high pressure fuel system reaches a predetermined controlled fuel pressure PfB (PfB = 7 MPa in this preferred embodiment) by the regulation function of the high pressure regulator 27 achieved after the fuel pressure Pf of the high pressure fuel system by driving the high pressure fuel pump 25 has been increased is derived. This time value is assumed to be the previously given value CS1 stored in the ROM 52 is stored with fixed data.

That is, the instantaneous value CS1 defines the expected time duration until the fuel pressure Pf of the high-pressure fuel system rises and reaches the controlled fuel pressure PfB passing through the high-pressure regulator 27 is defined after starting the engine when the high pressure fuel system is normal. In this preferred embodiment, the preset value CS1 is set at a value corresponding to 2 to 5 seconds.

Then, if CAS <CS1, that is, assuming that the time period after starting the engine has not reached a predetermined time defined by the previously set value CS1 and that the fuel pressure Pf of the high-pressure fuel system is the predetermined controlled fuel pressure PfB based on the high-pressure regulator 27 after starting the engine 1 by switching on the start switch 44 has not yet reached, the routine ends via step S16.

On the other hand, if CAS ≥ CS1 in step S22 and if the time period after starting the engine on the basis of turning on the start switch 44 reaches the predetermined time, that is, assuming that the fuel pressure Pf of the high pressure fuel system increases and that by the high pressure regulator 27 regulated controlled fuel pressure PfB after starting the engine 1 reaches, the routine goes to step S23, in which the initial diagnostic end flag FAS is set (FAS ← 1).

Then, in step S24, that of the fuel pressure sensor 35 detected fuel pressure Pf of the high-pressure fuel system to be compared with the current pressure PFS to check whether the actual fuel pressure Pf of the high-pressure fuel system has increased normally.

The preset pressure PFS1 is slightly lower than that by the high-pressure regulator 27 regulated controlled fuel pressure PfB (PfB = 7 MPa in this preferred embodiment) when the high-pressure fuel system is normal, or as the controlled fuel pressure PfB having a tolerance, and is previously in the ROM 52 saved as hard data. In this preferred embodiment, the preset pressure PFS1 is set in the range of 6 to 6.5 MPa, for example.

At Pf ≥ PFS, that is, when the fuel pressure Pf of the high-pressure fuel system exceeds the present pressure PFS in a predetermined period of time after starting the engine 1 has reached and when the fuel pressure Pf of the high-pressure fuel system has increased normally, it is determined that the high-pressure fuel system is normal, and the routine goes to step S25, in which the initial diagnosis OK flag FOK, the by the initial diagnosis immediately after starting the engine indicates that the high pressure fuel system is normal (FOK ← 1). Then the routine ends via step S16.

On the other hand, when Pf <PFS in step S24, that is, when the fuel pressure Pf of the high-pressure fuel system becomes the preset pressure PFS has not reached even though a predetermined period of time has elapsed after starting the engine, and when the fuel pressure Pf of the high pressure fuel system has not reached a predetermined pressure to which the fuel pressure Pf may increase when the high pressure fuel system is normal determines that the high-pressure fuel system is abnormal, and the routine goes to step S26.

In step S26, the high-pressure fuel system NG flag FHPNG denoting the abnormality of the high-pressure fuel system and the safety RAM 54 is stored as fault information, set (FHPNG ← 1), and the warning lamp 45 is turned on and off by one blink code with one blink period, the number of blinks per predetermined duration or the combination thereof providing information about the abnormality of the high pressure fuel system. Then the routine ends via step S16.

When the ignition switch 60 is turned on, the operation of the feed pump 24 started to pump the fuel through the high pressure pump 25 supply to the high pressure fuel system. If the engine 1 then by switching on the start switch 44 is started, then the high-pressure pump 25 driven, so that of the feed pump 24 supplied fuel through the high-pressure pump 25 is pressurized to supply it to the high-pressure fuel system.

Then, when the high pressure fuel system is normal, the fuel pressure Pf of the high pressure fuel system normally increases by driving the high pressure pump 25 like the full line of 17 shows to be higher than or equal to the current pressure PFS before the predetermined period of time defined by the preset value CS1 has elapsed.

When the fuel pressure Pf of the high pressure fuel system passes through the high pressure regulator 27 reaches regulated controlled fuel pressure PfB, the fuel pressure Pf of the high pressure fuel system at the controlled fuel pressure PfB by the pressure regulating function of the high pressure regulator 27 held.

If, in contrast, in the high-pressure pump 25 that forms the high pressure fuel system, there is a malfunction or if the high pressure regulator 28 is ineffective or out of the high pressure regulator 28 Fuel escapes or exits the high-pressure fuel system fuel, the pressure rise of the fuel pressure Pf of the high-pressure fuel system is delayed, as the dashed line in 17 or the fuel pressure Pf of the high-pressure fuel system does not rise to the regulated controlled fuel pressure PfB, and its pressure increase is interrupted in the middle.

If so the high pressure fuel system is abnormal, the fuel pressure reaches Pf of the high-pressure fuel system, the preset pressure PFS not, even if the predetermined period of time, which is defined by the preset value CS1 and in which the fuel pressure Pf of the high-pressure fuel system after the Starting the engine can increase enough when the high pressure fuel system is normal, has expired.

If So the time after starting the engine and the fuel pressure Pf of the high pressure fuel system can be determined by the abnormality of the high pressure fuel system early and be diagnosed precisely.

To Conclusion of the Initial diagnosis immediately after starting the engine by setting of the first diagnosis end flag FAS goes to the routine of step S17 to step S27. In steps S27 and S28, the fuel pressure becomes Pf of the high pressure fuel system with a lower limit PFL and an upper limit PFH, which is an allowable range Define the fuel pressure Pf to the abnormality of the high-pressure fuel system on the basis of the condition (2) described above.

there becomes the abnormality of the high pressure fuel system during engine operation diagnosed with the termination of the initial diagnosis.

After the engine starts and after the fuel pressure Pf of the high pressure fuel system has risen normally to that of the high pressure regulator 27 To achieve regulated controlled fuel pressure PfB, the fuel pressure Pf of the high pressure fuel system drops abnormally, such as the dot-dash line in FIG 17 indicates when during engine operation in the high pressure pump 25 or the high pressure regulator 27 that form the high pressure fuel system, foreign particles are generated due to the inclusion of the foreign matter in the fuel or when the high pressure regulator 27 itself is abnormal or fuel is leaking from the high-pressure fuel system.

Further, if the abnormality of the high pressure regulator 27 occurs, it is not possible to regulate the pressure of the fuel due to the high-pressure regulator 27 escaping fuel, so that the fuel pressure Pf of the high-pressure fuel system rises abnormally as the dashed-dotted line in 17 shows.

Therefore will be on completion of the initial diagnosis immediately after starting of the engine the fuel pressure Pf of the high-pressure fuel system with the lower limit PFL and the upper limit PFH, which is the permissible Define range, so that it is possible, the abnormality of the high-pressure fuel system to diagnose exactly.

In step S27, the current fuel pressure Pf of the high pressure fuel system received from the fuel pressure sensor 35 is detected, and the fuel pressure Pf is compared with the lower limit value PFL (eg, 4 ~ 5 MPa in this preferred embodiment), which has been previously set to be lower than the controlled fuel pressure PfB, and not is available when the high pressure fuel system is normal.

Then At step S28, the fuel pressure Pf becomes upper limit PFH (e.g., 9 MPa in this preferred embodiment), the was previously given so that he higher than that is controlled fuel pressure PfB and that is not available when the high pressure fuel system is normal.

If Pf <PFL or Pf> PFH, that is, if the fuel pressure Pf of the high-pressure fuel system is not in the usual fuel pressure range after starting the engine, the routine proceeds from the corresponding step to step S26 in which the high-pressure fuel system NG- Flag FHPNG is set (FHPNG ← 1) and the warning lamp 45 is turned on and off by a predetermined blink code to report the abnormality of the high-pressure fuel system. Then the routine ended via step S16.

If on the other hand, in steps S27 and S28, it is determined that PFL ≦ Pf ≦ PFH, d. H. when the fuel pressure Pf of the high-pressure fuel system in one permissible Area is, the routine goes to step S29. In step S29 and The following steps will be the compatibility of the air / fuel ratio A / F with the injection pulse duration Ti determines the abnormality of the high-pressure fuel system on the basis of the condition (3) described above.

If the high pressure pump 25 or the high pressure regulator 27 that form the high pressure fuel system is abnormal, or when fuel leaks from the high pressure fuel system, the fuel pressure Pf of the high pressure fuel that is the injector 13 is not maintained at the predetermined controlled fuel pressure. Therefore, when a drive signal having the same injection pulse width Ti is supplied to the injector, the fuel injection amount decreases by a drop in the fuel pressure Pf of the high-pressure fuel system corresponding to the injector 13 is supplied.

It is well known that in the fuel injection control the air-fuel ratio feedback control is built in, and if the actual Air / fuel ratio A / F with respect to the target air-fuel ratio due to the reduction the amount of fuel injection is lean becomes the injection pulse duration Ti enlarged to to perform the correction in the direction of fuel increase.

Thus, when the fuel pressure Pf of the high-pressure fuel system decreases due to the abnormality of the high-pressure fuel system, the air-fuel ratio A / F with respect to the target air-fuel ratio is lean by the reduction of the fuel injection amount. To correct this, the injection pulse width Ti is abnormally increased by the air-fuel ratio feedback correction, so that the air-fuel ratio A / F with the injection pulse duration Ti, which the injection valve opening period of the injector 13 defined, not compatible.

Although also the high pressure fuel to the injector 13 is supplied with a normally controlled fuel pressure, it is not possible to obtain a desired amount of fuel injection when the injector 13 is abnormal due to a defective injection valve opening or the like. Similarly, the injection pulse duration Ti is abnormally increased by the air-fuel ratio feedback correction, so that the air-fuel ratio A / F with the injection pulse duration Ti, which is the injection valve opening period of the injector 13 defined, not compatible.

If that is, the relationship between the air / fuel ratio A / F and the injection pulse duration Ti is determined while the air-fuel ratio feedback control is being executed, Is it possible, the abnormality to accurately diagnose the high pressure fuel system.

In step S28, it is determined whether the air-fuel ratio feedback control is being executed. During the open air / fuel ratio control, the inactive period of the linear O ₂ sensor 36 includes, the diagnostic conditions are not met, so that the routine via step S16 without the diagnosis of the high-pressure fuel system on the basis of the compatibility of the air / fuel ratio A / F with the Ein injection pulse duration Ti ends.

During the air-fuel ratio feedback control, the routine proceeds from step S28 to step S29 in which that of the linear O ₂ sensor 36 detected air / fuel ratio A / F is read out to be compared with a preset value (A / F) S and to determine whether the actual air / fuel ratio is a predetermined lean air / fuel ratio or more.

If then A / F <(A / F) S, it is determined that the Diagnostic conditions not met are, and the routine ends over Step S16.

On the other hand, when A / F ≥ (A / F) S, that is, when the air-fuel ratio A / F is greater than or equal to a lean air-fuel ratio defined by the preset value (A / F) S, becomes determines that the diagnosis conditions are satisfied, and the routine goes to step S30, in which the injection pulse duration Ti given by a fuel injection control routine, which will be described later, is read out to compare the injection pulse duration Ti with an upper limit value TiNGMAX which is usually not available at the lean air / fuel ratio to the abnormality of the high pressure fuel system including the injector 13 to diagnose.

If, during the air-fuel ratio feedback control, the injection pulse duration Ti defining the fuel injection amount is the upper limit value TiNGMAX, which is usually not available when the high-pressure fuel system including the injector 13 is normal, exceeds and abnormally long while the air / fuel ratio A / F is the predetermined lean air / fuel ratio, the fuel injection amount decreases due to the fuel pressure drop of the high pressure fuel system or the defective injection valve opening of the injector 13 from.

Thereby, the injection pulse width Ti is abnormally increased by the air-fuel ratio feedback correction although the air-fuel ratio is equal to or larger than the predetermined lean air-fuel ratio. In this case, it can be determined that the high pressure fuel system including the injector 13 is abnormal.

Therefore, the preset value (A / F) S and the upper limit value TiNGMAX are previously derived by simulation or experiments on the basis of the aforementioned compatibility to be fixed data in the ROM 52 to be saved.

Then, in step S30, when Ti> TiNGMAX, that is, when the injection pulse duration exceeds the predetermined value defined by the upper limit value TiNGMAX, while the air-fuel ratio A / F is equal to or higher than the predetermined lean air-fuel ratio is defined by the preset value (A / F) S, it is determined that the high-pressure fuel system including the injector 13 is abnormal, and the routine goes to step S31. Subsequently, the continued abnormal state is determined in steps S31 and S32.

In Step S31 is a continued abnormality duration count CNG for the clock control of continued duration of abnormality counted up (CNG ← CNG + 1). Then, in step S32, the continued abnormality duration count CNG compared with a preset value CS2.

The preset value CS2 defines a time value which can safely define that the high pressure fuel system including the injector 13 is abnormal by preventing the output of the linear O ₂ sensor 36 temporarily indicating a predetermined lean air-fuel ratio or more under the influence of disturbances or the like, or by a misdiagnosis due to the fact that the injection pulse duration Ti temporarily becomes an abnormal value under the influence of a disturbance or the like with respect to the response time delay of Has air / fuel ratio feedback control. The preset value CS2 is previously derived by simulation and experiments and in the ROM 52 saved with fixed data.

at CNG <CS2, d. H. if the continued duration of the abnormal condition, that the injection pulse duration Ti exceeds the upper limit TiMAX in the case of a lean air-fuel ratio, a predetermined period of time by the preset value CS2 is defined, not achieved, can not be determined that the high pressure fuel system is abnormal, and the abnormality is not determined, so that the Routine ends.

On the other hand, if CNG ≥ CS2, that is, if the continued duration of the abnormal state reaches the predetermined time defined by the preset value CS2, that is, if the injection pulse duration Ti exceeds the upper limit value TiNGMAX, which is usually unavailable when High pressure fuel system including the injector 13 is normal to continue this state for a predetermined period of time, while at the same time during the air / fuel ratio feedback control, the air / fuel ratio A / F is greater than or equal to the predetermined lean air / fuel ratio is defined by the preset value (A / F) S, it is determined that the high-pressure pump 25 or the high pressure regulator 27 that form the high-pressure fuel system, is abnormal or leaks fuel from the high-pressure fuel system, or the high-pressure fuel system due to the injector's faulty injection valve opening 13 is abnormal, and the routine goes to step S26.

In step S26, the high pressure fuel system NG flag FHPNG is set (FHPNG ← 1), and the warning lamp 45 is turned on and off after a predetermined blink code to report the abnormality of the high pressure fuel system. Then the routine ends via step S16.

Further can the diagnosis based on the behavior described above (1) and (2) the fuel pressure Pf of the high pressure fuel system are omitted, the abnormality of the high-pressure fuel system only on the basis of the compatibility of the air / fuel ratio To diagnose A / F with the injection pulse duration Ti, though the accuracy of the diagnosis is slightly worse.

Even if Ti ≦ TiNGMAX in step S30, d. H. even if the fuel pressure Pf of the high-pressure fuel system in the ordinary Range covered by the lower limit PFL and the upper limit PFH is defined, and even if the L A / F is greater or less is equal to the lean air / fuel ratio defined by the preset value (A / F) S, goes the routine, if the corresponding injection pulse duration Ti is given, d. H. if the conditions described above (2) and (3) not fulfilled to step S33 in which the reference to the initial diagnosis OK flag to determine if the high pressure fuel system has been determined even at the initial diagnosis immediately after starting the engine is normal.

at FOK = 0, d. H. if at the initial diagnosis immediately after the Starting the engine has been determined that the high-pressure fuel system is abnormal, can not be determined that the high-pressure fuel system is normal even if the conditions described above (2) and (3) not fulfilled are so that the Routine over Step S16 ends.

On the other hand, if FOK = 1 in step S33, that is, if it is determined in the initial diagnosis immediately after the start of the engine that the high-pressure fuel system is normal and if none of the above-described conditions (1) to (3) is satisfied, it is determined in that the high pressure fuel system is normal, and the routine goes to step S34, where the high pressure fuel system NG flag FHPNG designating the abnormality of the high pressure fuel system and in the safety RAM 54 is stored as fault data is set (FHPNG ← 0). If at this time the abnormality of the high pressure fuel system by turning on and off the predetermined code of the warning light 45 is displayed, it will be interrupted. Then the routine ends via step S16.

The result of the steps described above is that when the high pressure fuel system has any trouble, the warning light 45 is turned on and off to report the abnormality of the high-pressure fuel system, so that the driver can easily determine the disturbance.

Further, if troubleshooting is performed in a service operation such as a dealer, the serial monitor may 70 with the connector 65 for the external terminal, and the trouble data based on the high pressure fuel system NG flag FHPNG in the ECU 50 to accurately determine the failure of the high pressure fuel system.

After the repair of the corresponding defective part, the high-pressure fuel system NG flag FHPNG is passed through the serial monitor 70 reset. Further, in this preferred embodiment, even when the high-pressure fuel system NG flag FHPNG passes through the serial monitor 70 is not reset after the defective part is repaired, the high pressure fuel system NG flag FHPNG is reset in the high pressure fuel system diagnostic routine when the high pressure fuel system returns to the normal state.

On the other hand, when the high pressure fuel system with FHPNG = 0 is normal with reference to the high pressure fuel system NG flag FHPNG of the high pressure fuel system diagnosis routine in the bypass selector valve control routine according to FIG 5 , the ignition control routine according to 7 and the fuel injection control routine according to 8th , the bypass selector valve becomes 29 controlled in the closed state.

In response to the combustion system that is triggered by the combustion system selection routine according to 6 is selected, which is executed each time during a predetermined period of time and described later, also the injection pulse duration Ti for the injector 13 defining the appropriate amount of fuel injection for the respective combustion system, based on the engine operating condition, predetermined by the high-pressure regulator 27 regulated ge controlled fuel pressure PfB, and the fuel injection timing and the ignition timing are set so that they are suitable for the respective combustion system.

Further, when FHPNG = 1, that is, when the high pressure fuel system is abnormal, the bypass selector valve becomes 29 is controlled to the open state, and the injection pulse duration Ti suitable for the uniform premixed combustion is determined on the basis of the engine operating condition in response to the pressure of the low-pressure regulator 28 regulated low-pressure fuel specified.

To At this time, the fuel injection timing and the ignition timing, the for the uniform premixed Combustion are suitable, based on the engine operating condition given, so that the uniform premixed Burning on the early Injection, regardless of the choice of combustion system accomplished becomes.

The bypass selector valve control routine according to 5 will be described below. The bypass select valve control routine is executed at a predetermined time period (eg, 10 ms) after initialization of the system. In step S41, reference is made to the high pressure fuel system NG flag FHPNG. If the high pressure fuel system is normal at FHPNG = 0, the routine goes to step S42 where the solenoid of the bypass selector valve 29 de-energized (SOL ← OFF) to the bypass selector valve 29 close, and the routine ends.

Therefore, when the high-pressure fuel system is normal, the bypass selector valve becomes 29 closed to prevent fuel from the fuel bypass passage 21d exits, so that the high pressure fuel from the high pressure pump 25 pressurized and by the high pressure regulator 27 is regulated to a predetermined controlled fuel pressure, the injector 13 is supplied in the usual way.

On the other hand, if FHPNG = 1 in step S41, that is, if the high-pressure fuel system is abnormal, the routine goes to step S43, in which the solenoid of the bypass select valve 29 is energized (SOL ← ON) to the bypass selector valve 29 to open, and the routine ends.

Thus, when the high pressure fuel system is abnormal, the bypass selector valve becomes 29 Open to the connection between the high pressure fuel system and the low pressure fuel system via the fuel bypass passage 21d manufacture. Therefore, if the high pressure fuel system is abnormal, the low pressure fuel coming from the feed pump becomes low 24 is fed to through the low-pressure regulator 28 to be regulated to a predetermined fuel pressure, fed directly to the high pressure fuel system to the injector 13 to be fed, regardless of the high pressure fuel from the high pressure pump 25 and the high pressure regulator 27 is supplied.

Further, after the system initialization, the combustion system selecting routine becomes 6 each at a predetermined time (eg, every 10 ms) in parallel to the high-pressure fuel system diagnosis routine, and the stratified combustion or the uniform premixed combustion is selected as the combustion system based on the engine operating condition depending on the engine speed and the accelerator pedal position ALPH ,

These Combustion system dialing routine described below. First, in step S51, the reference becomes to a range designation value with the interpolation calculation carried out based on the current engine speed NE, by a range determination value L0 to determine which of the stratified combustion or uniform premixed combustion chosen becomes.

This region determination value L0 is a determination value as a reference for switching the combustion system to the stratified combustion or the uniform premixed combustion depending on the engine load. In this preferred embodiment, as an example of the engine load, an accelerator pedal position ALPH, which denotes a required load, and that of the accelerator pedal position sensor are used 31 detected accelerator pedal position ALPH is compared with the range determination value L0 to determine whether stratified combustion or uniform premixed combustion is selected. This selection of the combustion system is further performed by changing the fuel injection timing and the ignition timing.

As described above, the stratified combustion is a combustion system in which the fuel is injected into a respective cylinder in a compression stroke, so that the injection immediately before the ignition for igniting the rear end portion of the fuel spray by means of a spark plug 14 finished. Since stratified combustion utilizes only air around the fuel, it is possible to obtain stable combustion in a very small amount of fuel injection with respect to the amount of charge air, so that stratified combustion is suitable for engine operation at low speeds and low loads.

In contrast, the uniform premixed combustion is a combustion system in which the fuel is injected into a respective cylinder at a relatively early timing, ie, at the end of an exhaust stroke or in the intake stroke, so that the injected fuel is ignited after being stored in the combustion chamber 12 is distributed so that it is evenly mixed with air.

These uniform premixed Combustion has a big one Air quantity and can improve the engine performance, so that the uniform premixed Burning for engine operation during high engine speeds with high loads is suitable.

Therefore the range determination value table is obtained as follows. First becomes an appropriate accelerator pedal position for switching the combustion system between the stratified combustion or the uniform premixed combustion in through each area based on engine speed NE Derived simulation or experiments. This right accelerator pedal position is used as a range determination value L0 to specify a table the engine speed NE as a parameter for obtaining the area determination value table uses.

This area determination value table is stored in the ROM 52 stored as a series of addresses. An example of the range determination value table is in 18 shown. As in 18 5, the range determination value table stores range determination values L0 which become smaller as the engine speed NE increases.

Then, the routine goes to step S52 in which the accelerator position sensor 31 detected actual accelerator pedal position ALPH is compared with the range determination value L0.

For ALPH ≤ L0, ie during low engine speeds with low loads (the shaded area in 18 ), the stratified combustion is selected to improve the fuel consumption and the exhaust emission. To indicate that stratified combustion has been selected, a combustion system determination flag FCOMB is reset (FCOMB ← 0) in step S53, and the routine ends.

If on the other hand, in step S52, ALPH> L0, d. H. while high engine speeds with high loads, the uniform premixed Combustion chosen, to improve engine performance. To indicate that the uniform premixed combustion chosen is the combustion system determination flag FCOMB in Step S54 is set (FCOMB ← 1), and the routine ends.

When the high pressure fuel system is normal (FHPNG = 0), reference is made to the combustion system determination flag FCOMB set by the combustion system selection routine in each of the ignition control routine in FIG 7 and the fuel injection control routine in FIG 8th ,

When FCOMB = 0, that is, when the stratified combustion is selected, the injection pulse width Ti becomes the fuel injection amount for the injector suitable for the stratified combustion 13 defined based on the engine operating condition in response to the high-pressure regulator 27 regulated controlled fuel pressure PfB (PfB = 7 MPa in this preferred embodiment).

In addition, will the fuel injection timing for a compression stroke of Cylinder #i, in which an injection should be made, given, and the for the stratified combustion suitable ignition is based on the engine operating condition specified. During low engine speeds with low loads so the stratified combustion is carried out to the exhaust emission and to improve fuel consumption.

For FCOMB = 1, ie if the uniform premixed combustion is selected, will be for the injector 13 the injection pulse duration Ti, which defines the amount of fuel injection suitable for the uniform premixed combustion, based on the engine operating condition in response to the high-pressure regulator 27 regulated controlled fuel pressure PfB specified.

Further is the fuel injection timing at the end of a Auslaßhubs or in an intake stroke of a cylinder #i, in the injection take place should, given, and for the uniform premixed Combustion suitable ignition timing is specified. While high engine speeds with high loads is thus the uniform premixed Combustion carried out, to improve engine performance.

On the other hand, if the high pressure fuel system is abnormal (FHPNG = 1), since the low pressure fuel of the low pressure fuel system becomes the injector 13 directly by opening the bypass selector valve 29 is supplied, the injection pulse duration Ti, which is suitable for the uniform premixed combustion, on the basis of the engine operating condition in response to that by the regulating means 28 regulated pressure of the low pressure fuel specified (0.2 MPa in this preferred embodiment).

there are the fuel injection timing and the ignition timing, the for the uniform premixed Combustion are suitable, based on the engine operating condition given, so that the uniform premixed Burning on the early Injection, regardless of the choice of combustion system accomplished becomes.

Before the fuel injection control routine is described, the ignition control routine in FIG 7 described.

These Ignition control routine is executed at a predetermined period (for example, every 10 ms). First at step S61, the reference to the high-pressure fuel system NG flag is made FHPNG.

If FHPNG = 0, that is, if the high-pressure fuel system is normal, the routine goes to step S62, where reference is made to the combustion system determination flag FCOMB. If FCOMB = 0, that is, if the stratified combustion is selected, the routine goes to step S63. In step S63, based on the engine speed NE and the accelerator pedal position ALPH indicating a required load as the engine operating condition, the reference to one in the ROM is made 52 stored basic spark advance value table for the stratified combustion period with the interpolation calculation, and a basic spark advance value ADVBASE is set as the basic ignition timing suitable for the stratified combustion.

The basic spark advance value table for the stratified combustion period is set as follows. First, by simulation or experimentally, the optimum ignition timing for the stratified combustion in each engine operating region is first obtained on the basis of the accelerator pedal position ALPH and the engine rotational speed NE. The derived ignition timing suitable for the stratified combustion is utilized as the preignition ignition ADVBASE which defines the degree of ignition angle CA BTDC to provide a table using the accelerator pedal position ALPH and the engine speed NE as parameters. The table thus specified is the stratified combustion spark advance value table which is present at a series of addresses in the ROM 52 is stored.

Then, the routine goes to step S64 in which an ignition timing learning correction value ADVKR through which the ignition delay and the spark advance in each operating range depending on the presence of the knock sensor 32 detected knocking is specified by referring to an ignition timing learning correction value table with the interpolation correction stored in the safety RAM 54 has been stored on the basis of the accelerator pedal position ALPH and the engine speed NE.

Then at step S65, the ignition timing learning correction value ADVKR to the ground pre-ignition ADVBASE added to perform the learning correction to a controlled pre-ignition ADV pretend the ignition timing defined (ADV ← ADVBASE + ADVKR).

Then, in step S66, a discharge timing, ie, an ignition timing TADV defining the ignition timing, for the ignition coil 15 which is based on the input of the crank pulse θ1, based on the controlled pre-ignition ADV.

In this preferred embodiment, the ignition timing is controlled by a so-called timing system. As the 14 and 15 show the excitation start timing (dwell set) and the de-excitation timing (ignition timing; dwell cut) for the ignition coil 15 predetermined by a period of time after the input of the crank pulse θ1.

Here, since the controlled pre-ignition ADV is an angle information (BTDC ° CA), the controlled pre-ignition ADV must be converted to a period from the input of the crank pulse θ1 to the ignition. In this preferred embodiment, assuming that an input interval for the current crank pulse is Tθ and an angle between crank pulses corresponding to the input interval for the current crank pulse Tθ is θ, an ignition timing TADV is based on the input of the crank pulse θ1 according to the following formula from one time per rotation specified by 1 ° CA TADV ← (Tθ / θ) × (θ1-ADV) θ1: θ1 = 97 ° CA in this preferred embodiment.

Then, in step S67, the energization time DWL for the ignition coil 15 given by referring to a table with the interpolation calculation based on the battery voltage VB. The excitation time DWL defines the optimum excitation time for the primary current of the coil as a function of the battery voltage VB.

An example of this table is shown in step S67. At this time, when the battery voltage VB drops, the energization time DWL is prolonged to ensure the ignition energy, and when the battery voltage VB increases, the energization time DWL is shortened to reduce energy loss and heat generation of the ignition coil 15 to prevent.

Then, the routine goes to step S68 in which the energization time DWL from the ignition timing TADV is subtracted to set an energization start timing TDWL on the basis of the input of the crank pulse θ1 (TDWL ← TADV ← DWL), and the routine ends.

On the other hand, if FHPNG = 1 in step S61, that is, if the high pressure fuel system is abnormal, or if FHPNG = 0 in step S5 61 That is, when the high-pressure fuel system is normal, and when FCOMB = 1 at step S62, that is, when the uniform premixed combustion is selected, the routine goes to step S69.

In Step S69 becomes a basic pre-ignition ADVBASE, the as the basic ignition point serves that for the uniform premixed Combustible, given by referring to the basic spark advance value table for the uniform premixed Combustion with the interpolation calculation based on the accelerator pedal position ALPH, the engine speed NE and the required load as the engine operating condition designated.

The Basic ignition advance value table for the uniform premixed Combustion is set up as follows. First, beforehand Simulations or trials of the optimum ignition timing, which for the uniform premixed Combustion is suitable for each engine operating range based on the accelerator pedal position ALPH and the engine speed NE derived. The derived ignition timing, the for the uniform premixed Combustion is suitable as a basic pre-ignition ADVBASE used to a Table showing the accelerator pedal position ALPH and the engine speed Uses NE as a parameter.

The given table is the basic pre-ignition value table for the uniform premixed combustion, which is at a series of addresses in the ROM 52 is stored. Further, the base pre-ignition ADVBASE during the uniform premixed combustion shows a value earlier than the stratified combustion time.

Then the routine goes to step S64, an ignition timing learning correction value ADVKR is based on accelerator pedal position ALPH and engine speed NE specified by referring to the ignition timing learning correction value table with the interpolation calculation. Then, in steps S65 and S66, the ignition timing learning correction value ADVKR to the ground pre-ignition ADVBASE, the for the uniform premixed Combustion is suitable and has been specified in step S69, added to give a controlled pre-ignition ADV, and this controlled pre-ignition ADV, which is based on angle data, is based on an ignition timing TADV the input of the crank pulse θ1 transformed.

Then For example, in steps S67 and S68, an energization time DWL on the Base the battery voltage VB by referring to a table and the energization time DWL is set from the ignition timing Subtracts TADV to specify an energization start time TDWL. Then the routine ends.

As a result of the above-described steps, data on a cylinder to be ignited is determined in the cylinder determination / engine speed calculation routine from a θ1 crank pulse interrupt routine according to FIG 9 read, which is executed in synchronization with the input of the crank pulse θ1 and described later, and the current energization start timing TDWL and the ignition timing TADV given in the ignition control routine are read out.

Then For example, the energization start timing TDWL is input to an energization start timing clock for a timer to be ignited Cylinder set, and the ignition timing TADV becomes an ignition timing clock for the to be ignited Cylinder set. Furthermore, the respective clocks become synchronous started with the input of the crank pulse θ1, and for the combustion system suitable ignition is running.

Further, when the high-pressure fuel system is normal and the stratified combustion is selected, the reference to the ignition timing TADV defining the ignition timing is made in the fuel injection control routine according to FIG 8th and a fuel injection start timing IJST defining the fuel injection timing for each cylinder is set on the basis of the ignition timing TADV.

Hereinafter, the fuel injection control routine in FIG 8th described.

These Fuel injection control routine is each in a specific Period (eg every 10 ms). First, in step S71 to the high pressure fuel system NG flag FHPNG through the high pressure fuel system diagnostic routine Referenced.

at FHPNG = 0, d. H. if the high-pressure fuel system is normal, the routine goes to step S72 where the reference to the combustion system determination flag FCOMB he follows. For FCOMB = 0, d. H. if the stratified combustion is selected, the routine goes to step S73.

In step S73, based on the engine speed NE and the accelerator pedal position ALPH, the denotes a required load as the engine operating condition, the reference to the stratified combustion period basic fuel injection amount table with the interpolation calculation to specify a basic fuel injection amount GF (unit: g) corresponding to a fuel injection amount suitable for the stratified combustion and used for obtaining a predetermined engine output ,

The Bed combustion period basic fuel injection quantity table is set up as follows. First, beforehand by simulations or attempts to each engine operating range based on the engine speed NE and the accelerator pedal position ALPH the optimum injection quantity per stroke a cylinder for the stratified combustion is suitable and for obtaining a predetermined Engine power is suitable, derived.

The derived optimal fuel injection amount is used as the basic fuel injection amount GF to set up a map using the engine speed NE and the accelerator pedal position ALPH as parameters. The thus-prepared basic injection amount table is the stratified combustion period basic fuel injection amount table stored at a series of addresses in the ROM 52 is stored.

Then, the routine goes to step S74, referring to the basic injection pulse duration table with the interpolation calculation based on the basic fuel injection amount GF, and a basic injection pulse duration Tp (unit: ms) for the injector 13 is given to obtain the basic fuel injection amount GF.

The basic injection pulse duration table is set up as follows. The basic injection pulse duration Tp, which is an injector opening period of the injector 13 defined to obtain the basic fuel injection amount GF is previously derived by simulation or experiments for each area based on the basic fuel injection amount GF, while the pressure of the fuel flowing to the injector 13 is supplied by the high-pressure regulator 27 regulated controlled fuel pressure PfB is (PfB = 7 MPa in this preferred embodiment), so that the basic injection pulse duration table is set as a table using the basic fuel injection amount GF as a parameter and in the ROM 52 is stored at a series of addresses.

An example of the basic injection pulse duration table is shown in step S74. As the basic fuel injection quantity GF increases, it is necessary to set the basic injection pulse duration Tp, which is the injector basic opening period of the injector 13 defined to extend to obtain the basic fuel injection amount GF. Therefore, in the basic injection pulse duration table, the basic injection pulse duration Tp is stored as increasing with the increase of the basic fuel injection amount GF.

Further, there is an invalid time until the actual opening of the injector 13 after the delivery of an injection pulse duration signal to the injector, substantially constant regardless of the fuel pressure. If the basic injection pulse duration Tp is given, then the invalid time period is also corrected.

If FHPNG = 0, ie, if the high pressure fuel system is normal, the bypass selector valve will become 29 opened by the bypass selector valve control routine to prevent fuel from the fuel bypass passage 21d leaking, and the high pressure fuel, its pressure from the high pressure pump 25 is increased and by the high-pressure regulator 27 is regulated to a predetermined controlled fuel pressure, the injector 13 fed.

Therefore, at this time, when the basic fuel injection amount GF is converted to the basic injection pulse duration Tp so as to coincide with that by the high-pressure regulator 27 Regulated regulated fuel pressure PfB, it is possible, similar to conventional systems, to obtain a fuel injection amount corresponding to a required injection amount when the high pressure fuel system is normal.

Subsequently, in step S75, the reference to a fuel pressure correction factor table is made with the interpolation calculation on the basis of that from the fuel pressure sensor 35 detected fuel pressure Pf and the basic injection pulse duration Tp, and there is a fuel pressure correction factor Kp (unit: none) for the correction of the basic injection pulse duration Tp as a function of the fuel pressure Pf predetermined.

The Fuel pressure correction factor table is set up as follows. First, beforehand by simulation or trials in each area based on the fuel pressure Pf and the basic injection pulse duration Tp derived a factor that corrects the basic injection pulse duration Tp is suitable for obtaining the basic fuel injection amount GF. The derived factor is used as the fuel pressure correction factor Kp used to create a table showing the fuel pressure Pf and uses the basic injection pulse duration Tp as a parameter.

The thus prepared fuel pressure correction factor table is displayed at a series of addresses in the ROM 52 saved. Further, in this preferred embodiment, the fuel pressure used in the fuel pressure correction factor table in the range of, for example, 1 MPa to 9 MPa is set to the fuel pressure in a practical use range of the high-pressure fuel system with respect to the increase of the fuel pressure Pf at the start to cover the engine.

The basic injection pulse duration Tp is set to coincide with that by the high-pressure regulator 27 regulated controlled fuel pressure PfB (= 7 MPa), and the correction using the fuel pressure correction factor Kp is given as a multiplication term with respect to the basic injection pulse duration Tp as shown in step S76 and will be described later.

Therefore, when the fuel pressure Pf of the high-pressure fuel system, that of the fuel pressure sensor 35 is detected, the correction using the fuel pressure correction factor Kp is not executed, so that a value of Kp = 1.0 is stored in the corresponding fuel pressure range of the fuel pressure correction factor table becomes.

In the fuel pressure correction factor table are fuel pressure correction factors KP saved that gradually decrease from Kp = 1.0 one by one to the basic injection pulse duration Tp with increasing Reduce fuel pressure Pf in a range where the fuel pressure Pf higher as the controlled fuel pressure is PfB, and fuel pressure correction factors Kp, which gradually increase from Kp = 0, to increase the basic injection pulse duration Tp while the fuel pressure Pf becomes lower in a range in which the fuel pressure Pf is lower as the controlled fuel pressure is PfB.

However, in a range where the injection pulse duration Tp is very small (eg, Tp <0.6~0.7 ms in the preferred embodiment), when the fuel pressure Pf is high, the injector opening force of the injector increases 13 that is based on the fuel pressure Pf stronger than when the fuel pressure Pf is low. Therefore, when the fuel pressure Pf is high, the reduction of the effective opening time and the effective opening area of the injector 13 a greater influence on that of the injector 13 injected amount of fuel as if the fuel pressure Pf is low.

Further, if the injection pulse duration is the same, that of the injector decreases 13 injected fuel quantity decreases with increasing fuel pressure Pf. For this reason, in a range in which the basic injection pulse duration Tp falls below a predetermined value (Tp <0.6~0.7 ms in this preferred embodiment), fuel pressure coefficient Kp stored in the fuel pressure correction factor table increases with increasing fuel pressure Pf grow.

Then, the routine goes to step S76 where the basic injection pulse duration Tp is multiplied by the fuel pressure correction factor Kp to execute the fuel pressure correction and multiplied by an air-fuel ratio feedback correction factor KA / F to obtain the air-fuel ratio correction factor Kp. / Fuel Ratio Correction to a final injection pulse duration Ti for the injector 13 specify (Ti ← Tp × Kp × KA / F).

The air-fuel ratio feedback correction factor KA / F is well known and becomes dependent on the comparison results of a target air-fuel ratio given in accordance with the engine operating range with that of the linear O ₂ sensor 36 detected actual air / fuel ratio A / F predetermined. The air-fuel ratio feedback correction factor KA / F is for correcting the basic injection pulse duration Tp, so that the actual air-fuel ratio A / F approximates the target air-fuel ratio.

After that at step S77, a renewed reference to the combustion system determination flag FCOMB is made. For FCOMB = 0, d. H. if the stratified combustion is selected, the routine goes to step S78 in which the fuel injection end timing table based on the engine operating condition as a function of engine speed NE and the accelerator pedal position ALPH is searched for a fuel injection end timing IJEND (unit: ms) through the interpolation calculation.

The stratified combustion is a combustion system for injecting the fuel in a compression stroke to stop the fuel injection immediately before ignition, around the rear end portion of the fuel spray by means of a spark plug 14 to ignite.

In this preferred embodiment, after the fuel from the injector 13 is injected when the air-fuel mixture having an air-fuel ratio of a combustion region through the fuel jet, a region between discharge electrodes of the spark plug 14 achieved due to the intake air flow of the cylinder, the rear end portion of the force jet of material by means of the spark plug 14 ignited so that flames spread to achieve the stratified combustion, so that it is necessary to manage the interval between the end of the fuel injection and the ignition.

Therefore, the fuel injection end timing table is created as follows. First, by simulation or experiments for each engine operating range based on the engine rotational speed NE and the accelerator pedal position ALPH indicating a required load, the optimum fuel injection end timing before ignition suitable for the stratified combustion is previously derived, that is, a period until the rear End portion of the fuel spray from the air / fuel mixture through the cylinder intake air flow a portion between the discharge electrodes of the spark plug 14 achieved after the fuel from the injector 13 has been injected.

This time value is used as the fuel injection end timing IJEND to establish the fuel injection end timing table as a table using the engine speed NE and the accelerator pedal position ALPH as parameters. This fuel injection end timing table becomes at a series of addresses in the ROM 52 saved.

Then the routine goes to step S79 in which the ignition timing TADV from the ignition control routine is read out, and a fuel injection start timing IJST (Unit: ms), which is a fuel injection start timing the basis of the input of the crank pulse θ1 is defined by the reverse operation of the ignition timing TADV by means of the fuel injection end timing IJEND and the injection pulse duration Ti specified (IJST ← TADV ← (Ti + IJEND)). Then the routine ends.

In this preferred embodiment, the fuel injection start timing is controlled by the timing system, and when the stratified combustion is performed, the fuel injection start timing IJST for the respective cylinder is set by a period after the input of the crank pulse θ1, like the timing chart of FIG 14 shows.

there the fuel injection end timing IJEND denotes the interval between the end of the fuel injection and the ignition as a time value before the ignition. Therefore, the must Fuel injection end time IJEND in a period until converted to the beginning of the fuel injection after the input of the crank pulse θ1 become.

Out For this reason, in the preferred embodiment, the sum of the fuel injection end timing becomes IJEND and the injection pulse duration Ti from the ignition timing TADV, which is based on the input of the crank pulse θ1 has been given subtracted to the fuel injection start timing UJST on the basis of the input of the crank pulse θ1 pretend.

If on the other hand FHPNG = 0, d. H. if the high pressure fuel system is normal, and if FCOMB = 1 in step S72, d. H. if the uniform premixed Combustion chosen is the routine proceeds from step S72 to step S80 in which the Referring to a uniform premixed combustion period basic fuel injection amount table with the interpolation calculation based on the engine operating condition, based on the engine speed NE and the accelerator pedal position ALPH, is done to give a basic fuel injection amount GF (unit: g) pretend that for the uniform premixed Combustion suitable and applied to obtain a predetermined engine power becomes.

The Uniform-premixed combustion period basic fuel injection quantity table is created as follows. First, beforehand by simulation and Try for each range based on the engine speed NE and the accelerator pedal position ALPH, which indicate a required load, the optimum amount of fuel injection each stroke of a cylinder, for uniform pre-mixed combustion is adapted to obtain a predetermined engine power derived.

The derived optimal fuel injection amount is used as the basic fuel injection amount GF to make the uniform premixed combustion period basic fuel injection amount table as a table using the engine speed NE and the accelerator pedal position ALPH as parameters. This basic fuel injection amount table is displayed at a series of addresses in the ROM 52 saved.

After the basic fuel injection amount GF is set, the routine goes to step S74 in which the reference to the basic injection pulse duration table with the interpolation calculation based on the basic fuel injection amount GF is made, by a basic injection pulse duration Tp for the injector 13 to be used, which is used to obtain the basic fuel injection amount GF. Then, in step S75, the reference to the fuel pressure correction factor table is made with the interpolation calculation on the basis of that from the fuel pressure sensor 35 detected fuel pressure Pf and the basic injection pulse duration Tp to prefer a fuel pressure correction factor Kp ben.

Then, in step S76, the basic injection pulse duration Tp is multiplied by the fuel pressure correction factor Kp and the air-fuel ratio feedback correction factor KA / F to perform the force-pressure correction and the air-fuel ratio correction to obtain a final injection pulse duration Ti the injector 13 pretend.

In Step S77 then again refers to the combustion system determination flag FCOMB. For FCOMB = 1, d. H. when the uniform premixed combustion chosen is the routine goes from step S77 to step S81.

In Step S81 becomes the fuel injection start angle table the basis of engine operating condition based on engine speed NE and the accelerator pedal position ALPH, searches for a fuel injection start angle IJsa (unit: ° CA) on the basis of the upper compression dead center for each cylinder specify the interpolation calculation.

During the uniform premixed combustion the fuel injection is preferably terminated as soon as possible to the to distribute injected fuel so that the injected fuel is sufficiently mixed with fresh air. During high engine speeds However, with high loads is a large amount of fuel injection required, so that the Injection pulse duration Ti increases and required for a power stroke Time shorter becomes.

If that is, the fuel injection start timing is not appropriately managed fuel injection may start from the beginning to the middle in an exhaust stroke, which leads to, that the fuel is blown out into the exhaust system.

Thus, during the uniform premixed combustion, it is necessary to start the fuel injection at the end of the exhaust stroke or the intake stroke. In this preferred embodiment, the fuel injection start timing is managed at a crank angle before the compression top dead center based on the compression top dead center of the corresponding cylinder (see FIG 15 ).

Therefore the fuel injection start angle table is created as follows. First, beforehand by simulation or experiments for each Range based on engine speed NE and accelerator pedal position ALPH the optimal fuel injection starting angle before the upper one Compression dead center of the corresponding cylinder, for the uniform premixed Combustion is derived.

The derived optimal fuel injection start angle is used as the fuel injection start angle IJsa to make the fuel injection start angle table as a table using the engine speed NE and the accelerator pedal position ALPH as parameters. This fuel injection start angle table is displayed at a series of addresses in the ROM 52 saved.

Then becomes a time value for defining a fuel injection start timing in step S82 after the input of a reference crank pulse, a fuel injection start timing IJST (unit: ms) based on the fuel injection start angle IJsa given.

As described above, in this preferred embodiment, the fuel injection start timing is controlled by the timing system. Like the pulse diagram in 15 shows, during the uniform premixed combustion, the fuel injection start timing IJST for the respective cylinder is given by the time after the input of the crank pulse θ2, that is, two pulses before the corresponding cylinder.

There That is, the fuel injection start angle IJsa is crank angle information based on the upper compression dead center of the corresponding one Cylinder is converted into time, and the resulting Value is from a period of time from the input of the crank pulse θ2, two pulses in front of the corresponding cylinder, up to the upper compression dead center subtracted from the corresponding cylinder, which is a reference value for the default of the fuel injection start timing IJST. Thus, can a desired fuel injection start timing IJST be calculated.

Assuming that the current crank pulse input interval is Tθ and the angle between crank pulses is the current crank pulse input interval Tθ θ, a time period TθS from the input of the crank pulse θ2 may be two pulses before the respective cylinder, which is a reference value for setting the fuel injection start timing IJST. to the upper compression dead center of the corresponding cylinder by the following formula from a period of time per revolution of 1 ° CA (Tθ / θ). TθS = (Tθ / θ) × θS.

Further, θS is an angle from the crank pulse θ2, two pulses before the corresponding cylinder, to the compression top dead center of the corresponding cylinder, and is previously in the ROM 52 saved as fixed data. In this preferred embodiment, θS = 2 × 180 + 65 = 425 ° CA.

Therefore, a value ((Tθ / θ) - IJsa) obtained by converting the fuel injection start angle IJsa to time can be subtracted from the time value TθS (= (Tt / t) × θS) to obtain a fuel injection start timing IJST, and a fuel injection start timing IJST when the uniform premixed combustion is selected may be given by the following formula. IJST ← (Tθ / θ) × (θS - IJsa).

After this the fuel injection start timing IJST is given ends the routine.

If on the other hand, in step S71 FHPNG = 1, d. H. if the high pressure fuel system is abnormal, the routine goes regardless of which combustion system chosen is, from step S71 to step S83.

In step S83, the reference to an abnormal-period injection pulse duration table is made with the interpolation calculation based on the engine operating condition in response to the engine speed NE and the accelerator pedal position ALPH, and an injection pulse duration Ti (unit: ms) defining a fuel injection amount corresponding to the fuel injection amount uniform pre-mixed combustion is suitable and serves to obtain a predetermined engine power is at the pressure of a low-pressure regulating device 28 regulated low-pressure fuel specified.

The Abnormal period injection pulse duration table is set as follows. First, beforehand by simulation or experiments for each Range based on engine speed NE and accelerator pedal position ALPH indicating a required load, a fuel injection amount derived per cycle of a cylinder, which for the uniform premixed Combustion and to achieve a predetermined engine power suitable is.

Then, an injection pulse duration Ti used for obtaining the fuel injection amount is derived when the pressure of the injector 13 supplied fuel, the pressure through the low-pressure regulator 28 regulated low pressure fuel is (0.2 MPa in this preferred embodiment). Then, the abnormal-period injection pulse duration table is set as a table using the engine speed NE and the accelerator pedal position ALPH as parameters to operate on a series of addresses in the ROM 52 to be saved.

Thus, if FHPNG = 1, ie, if the high pressure fuel system is abnormal, the bypass selector valve will become 29 opened by the above-described bypass selector valve control routine, so that the low-pressure fuel of the low-pressure fuel system supplied by the pump 24 is supplied to the low-pressure regulator 28 to be regulated, the injector 13 is fed directly.

At this time, therefore, an injection pulse width Ti suitable for the uniform premixed combustion is determined on the basis of the engine operating condition based on the engine rotational speed NE and the accelerator pedal position ALPH in response to the pressure of the low-pressure regulator 28 regulated pressure of the low pressure fuel (0.2 MPa in this preferred embodiment) given.

Further, in the preferred embodiment, the injection pulse duration Ti, which is set when the high-pressure fuel system is abnormal, becomes dependent on the pressure of the injector 13 supplied low-pressure fuel (0.2 MPa) is set to be a value which is about 2 to 2.5 times the injection pulse duration Ti, in response to the high-pressure regulating device 27 regulated controlled fuel pressure PfB (7 MPa) is specified when the high pressure fuel system is normal.

There are also it is an upper limit for the one stored in the abnormal period injection pulse duration table Injection pulse duration, and the engine power is preferred by limits the upper limit of the injection pulse duration when the high-pressure fuel system is abnormal.

That is, when the high-pressure fuel system is abnormal, the engine output is limited by the upper limit of the injection pulse width Ti to prevent the amount of abnormality of the high-pressure fuel system from increasing and the safety control surely precludes the controllability of the fuel injection from deteriorating so that it is possible, a deterioration of the combustion state of the engine 1 to prevent.

After this the injection pulse duration Ti is specified, the routine is approaching Step S81 in which the reference to the fuel injection start angle table with the interpolation calculation based on the engine operating condition, based on the engine speed NE and the accelerator pedal position ALPH and a fuel injection start angle IJsa based on the upper one Compression dead point of the corresponding cylinder is specified. Then, in step S82, a fuel injection start timing IJST based on the fuel injection starting angle IJsa, and the routine ends.

So if FHPNG = 1, ie if the high pressure fuel system is abnormal, the bypass selector valve becomes 29 opened to the low-pressure fuel of the low-pressure fuel system the injector 13 feed the low pressure fuel into the cylinder (the combustion chamber 12 ).

If so, how 16 indicates the fuel injection timing is given in a compression stroke to perform the stratified combustion, the pressure difference between the pressure of the from the injector 13 injected low-pressure fuel and the cylinder pressure can not be sufficiently ensured, and the fuel injection amount can by the injector opening period of the injector 13 On the basis of the injection pulse duration Ti are not accurately metered, so that the controllability of the fuel injection is worse.

Thus, when the high-pressure fuel system is abnormal, an injection pulse width Ti suitable for the uniform premixed combustion becomes based on the engine operating state based on the engine rotational speed NE and the accelerator pedal position ALPH depending on the pressure of the low-pressure regulator 28 regulated low pressure fuel (0.2 MPa in this preferred embodiment), and a fuel injection timing is given at the end of an exhaust stroke or in the intake stroke to achieve the uniform premixed combustion.

Thus, the fuel injection amount by the injector opening period of the injector 13 is precisely metered on the basis of the injection pulse duration Ti, and it is thereby possible to avoid a deterioration of the controllability of the fuel injection.

As a result of the above-described steps, the ignition suitable for each of the combustion systems in the θ1-crank angle interrupt routine becomes 9 performed in synchronism with the input of the crank pulse θ1.

If FHPNG = 0, d. H. when the high pressure fuel system is normal is and if FCOMB = 0, d. H. if the stratified combustion is selected, become the data of a cylinder into which an injection takes place and the stratified combustion in the cylinder determination / engine speed calculation routine described above correspond, read, and the current fuel injection start timing IJST and the injection pulse duration Ti, which in the above-described Fuel injection control routine predetermined stratified combustion are determined by the θ1 crank pulse interrupt routine read.

Then is the fuel injection start timing UJST in the injection start timing for a clock Cylinder, in which the injection should be made, set, and the Injection pulse duration Ti becomes in the fuel injection timer set. Synchronous with the input of the crank pulse θ1 is the Inject start timing clock started to be used for stratified combustion perform appropriate fuel injection.

Hereinafter, the θ1-cranking pulse interrupt routine according to FIG 9 described.

This θ1 crank pulse interrupt routine is executed every time if a crank pulse θ1 is input according to the engine operation. In the steps S91 and S92 are data of a cylinder in which the injection in the cylinder determination / engine speed calculation routine and in the ignition control routine become the current energization start timing TDWL and the ignition timing TADV read out. Then, in the energization timing clock and the ignition timing clock a cylinder that ignited to be, the energization start time TDWL and the ignition timing TADV is set and the respective clocks are started.

Then at step S93, the reference to the high pressure fuel system NG flag FHPNG in FIG High-pressure fuel system diagnostic routine. For FHPNG = 1, d. H. if the high pressure fuel system is normal, the routine will increase Step S94 in which the reference to the combustion system determination flag FCOMB is done.

at FCOMB = 1, d. H. when the uniform premixed combustion chosen is, the routine ends immediately.

If whereas the high pressure fuel system is normal and when FCOMB = 0, d. H. if the stratified combustion is selected, the routine goes from step S94 to step S95, in which data of a detonator #i, in which during the Layer combustion an injection should take place and by the cylinder determination / engine speed calculation routine determines has been read, and the current fuel injection start time IJST set by the fuel injection control routine becomes read.

Then the fuel injection start timing UJST becomes an injection start timing clock for one Cylinder #i, into which an injection should take place, and the injection start timing timer is started.

Then at step S96, the current injection pulse duration Ti, which is in the fuel injection control routine has been specified, read, and the injection pulse duration Ti becomes a fuel injection timer for one Cylinder #i, in which an injection is to be made, set. Then the routine ends.

By the ignition control routine become the energization start timing TDWL and the ignition timing TADV based on the input of the crank pulse θ1 either while stratified combustion or uniform premixed combustion so given that they with a value set for each of the combustion system dependent on from the high pressure fuel system NG flag FHPNG and the combustion system determination flag FCOMB are suitable.

Of the Fuel injection start timing IJST and the injection pulse duration Ti are also given values for each of the combustion systems dependent on are suitable with the combustion system determination flag FCOMB.

If where FHPNG = 0, d. H. when the high pressure fuel system is normal is and if FCOMB = 0, d. H. if the stratified combustion is selected, become the fuel injection timing IJST and the injection pulse duration given for the stratified combustion are suitable. Also, in the steps S95 and S96, the current fuel injection start timing IJST and the injection pulse width Ti suitable for the stratified combustion are read out to enter the injection start timing clock or to be put the fuel injection clock. Furthermore, will at this time, the fuel injection start timing IJST predetermined on the basis of the input of the crank pulse θ1.

If So FHPNG = 0, d. H. when the high pressure fuel system is normal is and if FCOMB = 0, d. H. when the stratified combustion is selected the injection start timer is started in step S95 of this routine, which is executed in synchronization with the input of the crank pulse θ1 and the clock control of the fuel injection start timing IJST is started.

When FHPNG = 0, that is, when the high-pressure fuel system is normal and FCOMB = 0, that is, when the stratified combustion is selected, when this routine is executed by inputting the crank pulse θ1 at BTDC of the cylinder # 2, then Pulse diagram in 14 The cylinder to be ignited of the cylinders # 2 and the cylinder to be injected are the cylinder # 2, which was determined when the last crank pulse θ2 was input.

For easier understanding of the invention, as described in the 14 and 15 is shown, the same cylinder (cylinder # 2) will be described. When the high-pressure fuel system is normal and the stratified combustion is selected, the injection start timing timer for a corresponding cylinder is started by inputting the crank pulse θ1 at a crank angle before the compression top dead center of the corresponding cylinder 14 shows.

At this time, the fuel injection start timing IJST set by the reverse operation since the ignition timing TADV by means of the fuel injection control routine and suitable for the stratified combustion is set in the injection start timing timer. This fuel injection start timing IJST defines the timing suitable for performing the stratified combustion, wherein after the injection of the fuel before ignition on the basis of the ignition timing TADV, the fuel spray from the injector 13 due to the intake air flow of the cylinder, a region between discharge electrodes of the spark plug 14 reached, and the rear end portion of the fuel jet is through the spark plug 14 ignited.

When the time clocked by the injection start timing timer reaches the fuel injection start timing IJST, the IJST interrupt routine becomes 11 started. In step S11, the fuel injection timer for the corresponding cylinder is started, and the routine ends.

As a result, an injector driving signal based on the injection pulse duration Ti set in the fuel injection timer is sent to the injector 13 for the respective cylinder (see 14 ) so that a predetermined amount of fuel determined by the injection valve opening period corresponding to the injection pulse duration Ti is discharged from the injector 13 for the corresponding cylinder is injected.

If FHPNG = 0, ie, if the high pressure fuel system is normal, the bypass selector valve will become 29 that is in the fuel bypass channel 21d is closed by the bypass selector valve control routine, and a high pressure fuel passing through the high pressure pump 25 is pressurized to pass through the high pressure regulator 27 is regulated to a predetermined controlled pressure PfB, as in conventional systems the injector 13 fed.

Further, when FHPNG = 0, that is, when the high pressure fuel system is normal, and when FCOMB = 0, that is, when the stratified combustion is selected, the injection pulse duration Ti is set to be an appropriate value as follows. At this time, a basic fuel injection amount GF suitable for the stratified combustion is set by the fuel injection control routine based on the engine operating state based on the engine rotational speed NE and the accelerator pedal position ALPH, and the basic fuel injection amount GF becomes dependent on that by the high-pressure regulator 27 regulated controlled fuel pressure PfB converted into a basic injection pulse duration Tp.

Further, the basic injection pulse duration Tp is set so that the change of the actual fuel injection amount based on the fuel pressure Pf of the high pressure fuel system is compensated by the fuel pressure correction factor Kp. Then, the injection pulse duration Ti is set so that the of the injector 13 actually injected fuel injection quantity agrees with a required injection amount, which is given in dependence on the engine operating condition.

Thus, that is the injector 13 supplied fuel pressure with the injection pulse duration Ti compatible, and an appropriate amount of fuel corresponding to a required amount of fuel, which is metered depending on the injection pulse duration Ti and suitable for the stratified combustion and ensures a predetermined output power depending on the engine operating condition is from the injector 13 injected the corresponding cylinder.

If FHPNG = 0, d. H. when the high pressure fuel system is normal is and if FCOMB = 0, d. H. if the stratified combustion is selected, will the for the stratified combustion suitable ignition timing TADV by the Ignition control routine and the energization start timing TDWL is given by the ignition control routine based on the ignition timing TADV specified.

In Steps S91 and S92 of the θ1 crank pulse interrupt routine become the current energization start time TDWL and the current ignition timing TADV, the for the stratified combustion are read out, and in the excitation start timing clock or the Ignition timing clock for the corresponding cylinder, and the excitation start timing clock and the ignition timing clock are also synchronized with the input of the crank pulse θ1 at BTDC of the corresponding cylinder started.

Then, when the time clocked by the energization start timing timer reaches the energization start timing TDWL, the TDWL interrupt routine of FIG 12 started. In step S121, an excitation signal is sent to a corresponding cylinder from the ECU 50 by the excitation duration specified for the corresponding cylinder (see 14 ) to the detonator 16 output, and the excitation of the ignition coil 15 of the corresponding cylinder is started.

Thereafter, when the time clocked by the ignition timing timer reaches the ignition timing TADV which has been set in the ignition timing timer and is suitable for stratified combustion, the TADV interrupt routine of FIG 13 started. In step S131, the energization duration of the ignition coil becomes 15 of the corresponding cylinder interrupted, and the routine ends.

As a result, in the ignition coil 15 the corresponding cylinder generates a high secondary voltage, and the discharge electrode of the spark plug 14 the corresponding cylinder is ignited.

at FHPNG = 0, d. H. if the high-pressure fuel system is normal, and at FCOMB = 0, d. H. when the stratified combustion is selected the fuel injection start timing IJST by the reverse Operation based on the ignition timing TADV given, as described above.

Therefore, if the jet of fuel from the injector 13 certainly a range between the discharge electrodes of the spark plug 14 has reached as a result of the intake air flow of the cylinder, the spark plug 14 of the corresponding cylinder to burn the rear end portion of the fuel jet, so that flames spread in the air / fuel mixture of the fuel jet and perform the stratified combustion.

Consequently can while low engine speeds with low loads, if FHPNG = 0, d. H. if the high pressure fuel system is normal, the stratified combustion improve fuel economy and emissions.

On the other hand, when FHPNG = 0, that is, when the high-pressure fuel system is normal, and FCOMB = 1, that is, when the uniform premixed combustion is selected, or when FHPNG = 0, that is, when the high-pressure fuel system is abnormal, data of one cylinder, in to be injected corresponding to the uniform premixed combustion, and the actual fuel injection start timing IJST and the injection pulse duration Ti set in the fuel injection control routine which correspond to the uniform premixed combustion become lower in θ2 crank pulses refraction routine of 10 , which starts synchronously with the input of the crank pulse θ2, is read out.

Then the fuel injection start timing IJST becomes the injection start timing timer of the cylinder, into which an injection is to take place, and the injection pulse duration is put in the fuel injection timer. The injection start timing clock is started synchronously with the input of the crank pulse θ2, around the for the uniform premixed Combustion perform appropriate fuel injection.

Hereinafter, the θ2-cranking pulse interrupting routine according to FIG 10 described. In step S101, the high-pressure fuel system diagnosis routine refers to the high-pressure fuel system NG flag FHPNG. If FHPNG = 1, that is, if the high-pressure fuel system is abnormal, a jump is made to step S103. If FHPNG = 0, that is, if the high pressure fuel system is normal, the routine goes to step S102, where reference is made to the combustion system determination flag FCOMB.

If then FCOMB = 0, d. H. if the stratified combustion is selected, the routine ends immediately.

If whereas the high pressure fuel system is normal and FCOMB = 1, d. H. if the uniform premixed Combustion chosen is or if FHPNG = 1, d. H. if the high pressure fuel system is abnormal, the routine goes from the respective step to step S103, in which data of a cylinder #i, in the during the uniform premixed Combustion should be an injection and by the cylinder determination / engine speed calculation routine has been determined, and the current fuel injection start timing IJST given by the fuel injection control routine is, is read out. Furthermore the fuel injection start timing IJST becomes the injection start timing clock of the cylinder #i into which injection is to take place, and the injection start timing timer is started.

Then at step S104, the current injection pulse duration Ti, which is from the fuel injection control routine has been specified, read, and this injection pulse duration Ti becomes the fuel injection timer of the cylinder #i, into which an injection should take place. Then the routine ends.

at FHPNG = 0, d. H. if the high-pressure fuel system is normal, and at FCOMB = 1, d. H. when the uniform premixed combustion chosen is, or at FHPNG = 1, d. H. if the high pressure fuel system is abnormal, the fuel injection timing IJST generated by the reverse operation based on the upper compression dead center of the corresponding cylinder has been specified and for the uniform premixed Combustion is appropriate, given, and the injection pulse duration Ti to receive the fuel injection amount, which for the uniform premixed Combustion is suitable and to obtain the predetermined engine power, which corresponds to the engine operating condition at this time is set.

Therefore, in steps S103 and S104, the current fuel injection start timing IJST and the current injection pulse duration Ti suitable for the uniform premixed combustion are read out to be set in the injection start timing timer and the fuel injection timing generator. Besides, how will 15 1, the injection start timing clock of the corresponding cylinder is started by the input of the crank pulse θ2 two pulses before the compression top dead center of the corresponding cylinder.

Then, when the time clocked by the injection start timing timer reaches the fuel injection start timing IJST, the IJST interrupt routine becomes 11 is started, and the fuel injection timer of the corresponding cylinder is started in step S111. Then the routine ends.

As a result, an injector driving signal based on the injection pulse duration Ti set in the fuel injection timer is sent to the injector 13 of the corresponding cylinder (see 15 ), and a predetermined amount of fuel metered by the injector opening period corresponding to the injection pulse duration Ti is injected.

When FHPNG = 0, that is, when the high pressure fuel system is normal, it will be in the fuel bypass passage 21d provided bypass selector valve 29 opened by the bypass selector valve control routine, and a high pressure fuel supplied by the high pressure pump 25 pressurized by the high pressure regulator 27 is regulated to a predetermined controlled fuel pressure PfB, the injector 13 fed.

When FHPNG = 0, that is, when the high-pressure fuel system is normal, and when FCOMB = 1, that is, when the uniform premixed combustion is selected, the injection pulse duration Ti is set to be an appropriate value in the following manner. Thereby one for the uniform premixed combustion predetermined basic fuel injection amount GF of the fuel injection control routine on the basis of the engine operating state, based on the engine speed NE and the accelerator pedal position ALPH, given, and the basic fuel injection amount GF is in a basic injection pulse duration Tp depending on by high pressure regulator 27 converted regulated controlled fuel pressure PfB.

Further, the basic injection pulse duration Tp is set so that the change of the actual fuel injection amount based on the fuel pressure Pf of the high-pressure fuel system is compensated by the fuel pressure correction factor Kp. Then, the injection pulse duration Ti is set so that the actual fuel injection amount supplied by the injector 13 is injected, coincides with a required injection amount, which is predetermined depending on the engine operating condition.

So if FHPNG = 0, ie if the high pressure fuel system is normal, and if FCOMB = 1, ie if the uniform premixed combustion is selected, then the pressure of the injector is 13 supplied high-pressure fuel with the injection pulse duration Ti compatible, and of the injector 13 an appropriate amount of fuel corresponding to a required injection amount, which is metered in response to the injection pulse duration Ti so as to be suitable for the uniform premixed combustion, and the predetermined engine output having an air-fuel ratio is injected into the corresponding cylinder achieved depending on the engine operating condition at this time.

On the other hand, when FHPNG = 1, that is, when the high-pressure fuel system is abnormal, it becomes in the fuel bypass passage 21d bypass valve 29 from the bypass selector valve control routine to open the connection between the high pressure fuel system and the low pressure fuel system via the fuel bypass passage 21d so that low pressure fuel coming from the feed pump 24 fed and through the low pressure regulator 28 has been regulated to a predetermined fuel pressure, the injector 13 regardless of the high pressure fuel supplied by the high pressure pump and the high pressure regulator 27 is supplied.

When the high pressure fuel system is abnormal, the injection pulse duration Ti from the fuel injection control routine is set to be commensurate with the pressure of the low pressure fuel supplied from the low pressure regulator based on the engine operating condition based on the engine speed NE and the accelerator pedal position ALPH 28 is regulated, consistent and suitable for uniform premixed combustion.

In addition, the injection pulse duration Ti is set so that the injected from the injector actual fuel injection amount corresponds to a required injection quantity, while the pressure of the injector 13 supplied fuel, the pressure of a through the low-pressure regulator 28 regulated low pressure fuel is.

Thus, even if FHPNG = 1, that is, even if the high-pressure fuel system is abnormal, the pressure of the low-pressure fuel supplied to the injector is compatible with the injection pulse duration Ti and a suitable amount of fuel corresponding to a required injection amount, which is metered in response to the injection pulse duration Ti is that it is suitable for the uniform premixed combustion, and that ensures a predetermined engine power in response to the current engine operating condition, is from the injector 13 injected the corresponding cylinder.

Further, at this time, since the fuel injection timing at the end of an exhaust stroke or an intake stroke where the cylinder pressure is low is set by the fuel injection start timing IJST depending on the uniform premixed combustion, the pressure difference between the pressure of the fuel injection is 13 sufficiently ensured injected low-pressure fuel and the cylinder pressure, and the fuel injection amount can by the injector opening period of the injector 13 be accurately metered, so that it is possible to prevent deterioration of the controllability of the fuel injection.

After that becomes the θ1 crank pulse interrupt routine by the crank pulse θ1 started at BTCD of the corresponding cylinder. Then the current energization start timing TDWL and ignition timing TADV in the energization start timing clock and the ignition timing for the corresponding Cylinder set, and the respective clocks are started.

When FHPNG = 0, ie when the high pressure fuel system is normal and at FCOMB = 1, ie when uniform premixed combustion is selected, or at FHPNG = 1, ie when the high pressure fuel system is abnormal, the ignition timing is TADV, is suitable for the uniform premixed combustion, and the Excitation start time TDWL has been predetermined on the basis of the ignition timing TADV by the ignition control routine.

Therefore become the θ1-crank pulse interrupt routine in steps S91 and S92 the current energization start time TDWL and the actual ignition timing TADV, the for the uniform premixed Combustion are read out to enter the excitation start timing clock or the ignition timing clock for the respective cylinder, and the energization start timing clock and the ignition timing for the corresponding Cylinders become synchronous with the input of the crank pulse θ1 at BTDC of corresponding cylinder started.

Then, when the time clocked by the energization start timer reaches the energization start timing TDWL, the TDWL interrupt routine of FIG 12 started. In step S121, an excitation signal for the corresponding cylinder is output from the ECU 50 to the detonator 16 is output by the closing angle setting of the corresponding cylinder (see 15 ), and the energization time (the closing angle) of the ignition coil 15 of the corresponding cylinder is started.

Thereafter, the timing clocked by the ignition timing timer reaches the ignition timing TADV set in the ignition timing timer so as to be adapted to the uniform premixed combustion, the TADV interrupt routine of FIG 13 is started, and in step S131, the energization of the ignition coil 15 interrupted the corresponding cylinder. Thus, in the ignition coil 15 the corresponding cylinder generates a high secondary voltage, and the discharge electrode of the spark plug 14 the corresponding cylinder is ignited.

As As described above, the fuel injection timing IJST is during uniform premixed Combustion to the exhaust stroke end or in the intake stroke by the reverse operation based on the given the upper compression dead center of the corresponding cylinder, and the fuel injection is started when a suitable uniform premixed Condition of the fuel jet and fresh air during ignition can be obtained.

Therefore, in the state where the injected fuel is in the combustion chamber 12 is sufficiently mixed with fresh air, that is, in the uniform premixed state in which the fuel jet is sufficiently distributed, carried out the ignition, so that the air / fuel mixture is burned in the uniform premixed combustion immediately.

If then FHPNG = 0, d. H. when the high-pressure fuel system during high Engine speeds with high loads normal, can be a high average effective pressure through uniform premixed combustion be achieved so that it is possible to ensure a required engine power and engine power to improve.

In addition, when FHPNG = 1, that is, when the high-pressure fuel system is abnormal, the low-pressure fuel of the low-pressure fuel system becomes the injector 13 supplied directly, and the uniform premixed combustion is performed by the early injection regardless of the choice of the fuel combustion system, so that it is possible to prevent deterioration of the controllability of the fuel injection due to the abnormal fuel pressure of the high-pressure fuel system and a deterioration of the engine combustion state.

SECOND EMBODIMENT

With reference to 24 Hereinafter, the second preferred embodiment of the present invention will be described.

In the first preferred embodiment described above, the abnormal period injection pulse duration table is provided to store therein the injection pulse duration Ti suitable for obtaining the required fuel injection amount suitable for the uniform premixed combustion with the pressure of the low pressure fuel generated by the low pressure regulator 28 is regulated, using the engine speed NE and the accelerator pedal position ALPH as a parameter.

At FHPNG = 1, that is, when the high-pressure fuel system is abnormal, the injection pulse width Ti suitable for the uniform premixed combustion is calculated based on the engine operating state based on the engine rotational speed NE and the accelerator pedal position ALPH depending on the pressure of the low-pressure fuel. regulator 28 regulated low pressure fuel given with reference to the Abnormal Period Injection Pulse Duration Table.

On the other hand, in the present preferred embodiment, when the high pressure fuel system is abnormal, similarly to the case where the high pressure fuel system is normal and the uniform premixed combustion is selected, a basic fuel injection amount GF suitable for uniform premixed combustion is uniformly mixed Preset combustion period basic injection amount table, and the basic fuel injection amount GF is performed by the basic injection pulse duration table into a basic injection pulse duration Tp as a function of one by the high pressure regulator 27 regulated controlled fuel pressure PfB specified.

Further, when the high-pressure fuel system is abnormal, an abnormal period correction factor KFS for the correction for increasing the basic injection pulse duration Tp is changed depending on the pressure of one by the low-pressure regulator 28 regulated low-pressure fuel specified. This abnormal period correction factor KFS is introduced into an operation equation for the injection pulse duration Ti, so that the basic injection pulse duration Tp, which depends on that by the high-pressure regulator 27 regulated controlled fuel pressure PfB has been specified to be corrected in response to the pressure of the low-pressure regulator 28 regulated low-pressure fuel to be briefly set to an injection pulse duration Ti, which is suitable for the uniform premixed combustion, depending on the pressure of the low-pressure fuel supplied by the low-pressure regulator 28 is regulated to pretend when the high pressure fuel system is abnormal.

It is thus possible to omit the abnormal-period injection pulse duration table so that the man-hours for setting the data of the injection pulse width Ti stored in the abnormal-period injection pulse duration table and the storage capacity of the memory (ROM 52 ) used by the table can be reduced.

There Further, a single abnormal period correction factor is used can be setting procedures the injection pulse duration Ti during normal and abnormal states shared to some extent the high-pressure fuel system be opposed to the controller the first preferred embodiment simplify so that the needed to set up the data Man hours can be significantly reduced.

More specifically, in this preferred embodiment, a fuel injection control routine according to FIG 24 instead of the fuel injection control routine according to FIG 8th used in the first preferred embodiment.

Further, the other routines are the same as in the first preferred embodiment, so that their descriptions are omitted. In addition, in the fuel injection control routine according to FIG 24 for the same steps as in the first preferred embodiment, the same reference numerals are used, and the detailed description is omitted.

Hereinafter, the fuel injection control routine of FIG 24 described.

As in the first preferred embodiment, the fuel injection control routine becomes 24 at every predetermined period (eg 10 ms) after system initialization. First, in step S71, the reference to a high pressure fuel system NG flag FHPNG is made. When FHPNG = 0, that is, when the high-pressure fuel system is normal, the routine goes to step S201 in which an abnormal period correction factor KFS for increasing a basic injection pulse duration Tp during the abnormal state of the high-pressure fuel system is set to "1.0 "(KFS ← 0) is given.

Thus, if FHPNG = 0, ie if the high pressure fuel system is normal, the bypass selector valve will become 29 closed by the bypass selector valve control routine, so that a high pressure fuel passing through the high pressure regulator 27 is regulated, the injector 13 is supplied. The basic injection pulse duration Tp, which is an object to be corrected by the abnormal period correction factor KFS, is determined in response to a controlled fuel pressure PfB (= 7 MPa) obtained from the H 27 regulated by means of a process to be described. Further, the abnormal period correction factor Kp is given as a multiplication term for the basic injection pulse duration Tp, as shown in step S202 which will be described later.

If So FHPNG = 0, d. H. when the high pressure fuel system is normal is set, the abnormal period correction factor KFS is set to "1.0", so that in the Abnormal-period correction factor KFS no corrections made.

After that the routine goes to step S72, where reference to a combustion system determination flag FCOMB is done.

If then FCOMB = 0, d. H. if the stratified combustion is selected, the routine goes to step S72 in which the reference to a stratified combustion period basic injection amount table with the interpolation calculation based on the engine operating condition, based on the engine speed NE and the accelerator pedal position ALPH, takes place, by a basic fuel injection amount GF according to a required one Specify injection quantity for the stratified combustion is suitable and for obtaining a predetermined Motor power is used.

After the basic fuel injection amount GF is set, the routine goes to step S74, where reference is made to a basic injection pulse duration table with the interpolation calculation based on the basic fuel injection amount GF for the injector 13 to specify a basic injection pulse duration Tp serving to supply the basic fuel injection amount GF with one by the high-pressure regulator 27 to obtain regulated controlled fuel pressure PfB (= 7 MPa).

Subsequently, in step S75, a reference is made to a fuel pressure correction factor table with the interpolation calculation based on one of the fuel pressure sensor 35 detected fuel pressure Pf and the basic injection pulse duration Tp to specify a fuel pressure correction factor Kp.

As well as in the first preferred embodiment, the range includes of the fuel pressure as a parameter in the fuel pressure correction factor table Fuel pressures in a practical range of use of the high pressure fuel system with regard to the rising operation of the fuel pressure Pf during the Startup, so that he in the range of z. B. 1 MPa to 9 MPa is specified.

Then, in step S202, the basic injection pulse duration Tp is multiplied by the fuel pressure correction factor Kp and an air-fuel ratio correction factor KA / F to perform the pressure correction and the air-fuel ratio correction, and the correction factor KFS multiplied given in step S201 by a final injection pulse duration Ti for the injector 13 specify (Ti ← Tp × Kp × KA / F × KFS).

At this time, the abnormal period correction factor KFS has been set as described above at KFS = 1.0. Thus, if the high-pressure fuel system is normal and the stratified combustion is selected, the increase correction using the abnormal period correction factor KFS is not performed, and an injection pulse width Ti suitable for the stratified combustion becomes dependent on that by the high-pressure regulator 27 regulated controlled fuel pressure PfB specified.

With FHPNG = 0, that is, when the high pressure fuel system is normal, so will the bypass selector valve 29 that is in the fuel bypass channel 21d is closed by the bypass selector valve control routine, and the high pressure fuel supplied by the high pressure pump 25 pressurized to pass through the high pressure regulator 27 to be regulated to the predetermined controlled fuel pressure PfB is supplied to the injector in the usual way.

Then, when FHPNG = 0, that is, when the high-pressure fuel system is normal, and when FCOMB = 0, that is, when the stratified combustion is selected, the injection pulse duration Ti is set to be an appropriate value as follows. Here, a basic fuel injection amount GF suitable for the stratified combustion is set on the basis of the engine operating condition based on the engine rotational speed NE and the accelerator pedal position ALPH, and the basic fuel injection amount GF becomes dependent on that by the high-pressure regulator 27 regulated controlled fuel pressure PfB converted into a basic injection pulse duration Tp.

Further, the basic injection pulse duration Tp is set so that the change of the actual fuel injection amount is compensated based on the fuel pressure Pf of the high-pressure fuel system by the fuel pressure correction factor Kg. Then, the injection pulse duration Ti is set so that the actual fuel injection amount supplied by the injector 13 is injected, agrees with a required amount of fuel, which is given in dependence on the engine operating condition.

Thus, that is the injector 13 supplied fuel pressure with the injection pulse duration Ti compatible, and at FHPNG = 0, ie when the high-pressure fuel system is normal, and at FCOMB = 0, that is, when the stratified combustion is selected, a suitable amount of fuel that corresponds to the required injection quantity and to the stratified combustion is adjusted and ensures a predetermined output power corresponding to the engine operating condition at this time, from the injector 13 of the respective cylinder are injected similarly as in the first preferred embodiment.

Then the reference to the high pressure fuel system NG flag is again made in step S203 FHPNG. For FHPNG = 0, d. H. if the high pressure fuel system is normal, the routine goes to step S77, in which the reference to the combustion system determination flag FCOMB.

If FCOMB = 0, that is, if stratified combustion is selected, the routine goes to step S78 where reference to a fuel injection end timing table with the interpolation calculation based on the engine operating condition based on the engine speed NE and the accelerator pedal position ALPH is made Kraftstoffeinsprit zende time IJEND.

Then at step S79, an ignition timing TADV from the ignition control routine and a fuel injection start timing IJST is based on the input of the crank pulse θ1, by subtraction the fuel injection timing IJEND and the injection pulse duration Ti from the ignition point TADV specified. Then the routine ends.

If on the other hand FHPNG = 0, d. H. if the high pressure fuel system is normal, and if FCOMB = 1 in step S72, d. H. if the uniform premixed Combustion chosen is the routine proceeds from step S72 to step S80 in which the Referring to a uniform premixed combustion period basic injection amount table with the interpolation calculation based on the engine operating condition, based on the engine speed NE and the accelerator pedal position ALPH, takes place, and a basic fuel injection amount GF, which is for the uniform premixed Combustion is suitable and to obtain a predetermined output air / fuel ratio is used is specified.

After the basic fuel injection amount GF is set, the routine goes to step S74 in which the reference to a basic injection pulse duration table is made with the interpolation calculation based on the basic fuel injection amount GF, by a basic injection pulse duration Tp for the injector 13 to be given to obtain the basic fuel injection amount GF with a by the high-pressure regulator 27 regulated controlled fuel pressure PfB is used.

Then, in step S75, the reference to a fuel pressure correction factor table is made with the interpolation calculation on the basis of that from the fuel pressure sensor 35 detected fuel pressure Pf and the basic injection pulse duration Tp to specify a fuel pressure correction factor Kp.

Then, in step S202, the basic injection pulse duration Tp is multiplied by the fuel pressure correction factor Kp, an air-fuel ratio feedback correction factor KA / F and an abnormal period correction factor KFS by a final injection pulse duration Ti for the injector 13 specify (Ti ← Tp × Kp × KA / F × KFS).

At this time, an abnormal period correction factor KFS is set at KFS = 1.0 in step S201. Therefore, when the high-pressure fuel system is normal and when the uniform premixed combustion is selected, the increase correction using the abnormal period correction factor KFS is not performed, and an injection pulse duration Ti suitable for the uniform premixed combustion becomes dependent on that by the high pressure -Reguliereinrichtung 27 regulated controlled fuel pressure PfB specified.

If FHPNG = 0, ie, if the high pressure fuel system is normal, the bypass selector valve will become 29 that is in the fuel bypass channel 21d is provided, opened by the bypass selector valve control routine, and one of the high pressure pump 25 pressurized high pressure fuel passing through the high pressure regulator 27 To regulate to a predetermined controlled fuel pressure PfB is the injector 13 fed.

Then, when FHPNG = 0, that is, when the high pressure fuel system is normal, and when FCOMB = 1, that is, when the uniform premixed combustion is selected, the injection pulse duration Ti is set to be an appropriate value as follows. Here, a basic fuel injection amount GF suitable for the uniform premixed combustion is set on the basis of the engine operating state based on the engine rotational speed NE and the accelerator pedal position ALPH, and the basic fuel injection amount GF is determined by the high-pressure fuel injection amount GF. regulator 27 regulated fuel pressure PfB converted into a basic injection pulse duration Tp.

Further, the basic injection pulse duration Tp is set so that the change of the actual fuel injection amount based on the fuel pressure Pf of the high pressure fuel system is compensated by the fuel pressure correction factor Kp. Then, the injection pulse duration Ti is set so that the of the injector 13 actually injected fuel quantity coincides with a required injection amount, which is predetermined in dependence on the engine operating condition.

Thus, the pressure of the injector 13 supplied high-pressure fuel with the injection pulse duration Ti compatible, and a suitable fuel amount corresponding to a required amount of fuel, which is metered in dependence on the injection pulse duration Ti and is suitable for the uniform premixed combustion and a predetermined engine output air-fuel ratio depending on achieved the engine operating condition at this time, can from the injector 13 be injected of the corresponding cylinder.

Then the reference to the high pressure fuel system NG flag is made again in step S203 FHPNG. For FHPNG = 0, d. H. if the high pressure fuel system is normal, the reference to a combustion system determination flag FCOMB is made in step S77. For FCOMB = 1, d. H. when the uniform premixed combustion chosen is the routine goes from step S77 to step S81.

In Step S81, reference is made to a fuel injection start angle table with the interpolation calculation based on the engine operating condition, based on the engine speed NE and the accelerator pedal position ALPH, by a fuel injection starting angle IJsa based on the upper compression dead center to specify the appropriate cylinder. Subsequently, will in step S82, a fuel injection start timing IJST on Basis of the fuel injection starting angle IJsa given, and the Routine ends.

If on the other hand, in step S71, FHPNG = 1, d. H. if the high pressure fuel system is abnormal, the routine goes regardless of the choice of the combustion system to step S204.

In Step S204 then becomes an abnormal period correction factor KFS redefined with a previously set value KSET (KFS ← KSET).

At FHPNG = 1, that is, when the high pressure fuel system is abnormal, the bypass selector valve becomes 29 opened by the bypass selector valve control routine, so that a through the low-pressure regulator 28 regulated low-pressure fuel to the injector 13 is supplied.

In addition, in this preferred embodiment, even when the high-pressure fuel system is abnormal, a basic fuel injection amount GF suitable for the uniform premixed combustion is given by a uniform-premixed-combustion-period basic injection amount table, and the basic fuel injection amount GF becomes by the basic injection pulse duration table in response to the high-pressure regulator 27 regulated controlled fuel pressure PfB (= 7 MPa) is converted into a basic injection pulse duration Tp.

In addition, the basic injection pulse duration Tp, which is dependent on that by the high pressure regulator 27 regulated controlled fuel pressure PfB (= 7 MPa) has been corrected so as to be increased by the abnormal period correction factor KFS depending on the pressure of the low-pressure fuel (= 0.2 MPa) flowing through the low-pressure regulator 28 is regulated to set an injection pulse duration Ti, the pressure of the low-pressure regulating device 28 corresponds to regulated low-pressure fuel and is suitable for uniform premixed combustion, so that the injection 13 supplied fuel pressure with the injection pulse duration Ti is compatible.

Thus, the preset value KSET for setting the abnormal period correction factor KFS when the high-pressure fuel system is abnormal is set as follows. First, a coefficient value for correction for increasing the basic injection pulse duration Tp in response to the high-pressure regulator 27 regulated controlled fuel pressure PfB (= 7 MPa) has been preset to obtain the same amount of force injection as a required injection quantity previously derived by simulation or testing, while at the same time passing through the low pressure regulator 28 Regulated low-pressure fuel to the injector 13 is supplied.

The derived coefficient value is given as the preset value KSET to be stored in the ROM 52 to be stored with fixed data. In this preferred embodiment, the preset value KSET is given for example with KSET = 2 ~ 2.5.

After this the Abnormal Period Correction Factor KFS is given, the Routine to step S80 in which the reference to a uniform-premixed combustion period basic injection amount table with the interpolation calculation based on the engine speed NE and the accelerator pedal position ALPH is done by a basic amount of fuel injection GF pretend for the uniform premixed Combustion is suitable and to obtain a predetermined output power is being used.

Then, in step S74, the reference to a basic injection pulse duration table with the interpolation calculation based on the basic fuel injection amount GF is made by a basic injection pulse duration Tp corresponding to one by the high-pressure regulator 27 regulated controlled fuel pressure PfB (= 7 MPa).

Further, in step S75, the reference to a fuel pressure correction factor table is made with the interpolation calculation on the basis of that from the fuel pressure sensor 35 detected fuel pressure Pf and the basic injection pulse duration Tp to set a fuel pressure correction factor Kp, and the routine goes to step S202.

In step S202, the basic injection IM pulse duration Tp multiplied by the fuel pressure correction factor Kp and an air-fuel ratio feedback correction factor KA / F and multiplied by the abnormal period correction factor KFS newly set in step S204, so that the basic injection pulse duration Tp depending on which by the high-pressure regulating device 27 regulated controlled fuel pressure PfB (= 7 MPa) has been specified, is corrected in response to by the low-pressure regulator 28 regulated pressure of the low pressure fuel (= 0.2 MPa) to be increased to a final injection pulse duration Ti for the injector 13 specify (Ti ← Tp × Kp × KA / F × KFS).

Thus, if FHPNG = 1, ie if the high pressure fuel system is abnormal, the injection pulse duration Ti may be set to have an appropriate value such that the actual amount of fuel injected to the injector 13 is supplied in accordance with the required injection amount, which is given in response to the engine operating condition, in response to the low-pressure regulating device 28 regulated pressure of the low-pressure fuel, the injector 13 is to be supplied.

Thus, that is the injector 13 supplied fuel pressure with the injection pulse duration Ti compatible, and even at FHPNG = 1, that is, even if the high-pressure fuel system is abnormal, a suitable amount of fuel corresponding to a required injection amount, which is metered in response to the injection pulse duration Ti and for the uniform premixed Combustion is suitable and ensures a predetermined output power depending on the engine operating condition, from the injector 13 be injected of the corresponding cylinder.

After that the reference to the high pressure fuel system NG flag is made again in step S203 FHPNG. For FHPNG = 1, d. H. if the high pressure fuel system is abnormal, the routine goes to step S205 in which the injection pulse duration Ti is compared with an upper limit TiMAX given is to limit the engine power.

Thus, when the high-pressure fuel system is abnormal, the upper limit of the injection pulse duration Ti is made by the upper limit value TiMAX to limit the engine output and prevent an increase in the magnitude of the abnormality of the high-pressure fuel system and certainly deterioration of the controllability of the fuel injection due to to prevent the safety control, so that it is possible to deteriorate the combustion state of the engine 1 to prevent.

If then in step S205 Ti ≦ TiAX, d. H. when the injection pulse duration Ti is not higher than the upper limit TiMAX is, the routine jumps directly to step S81, without the upper limit to execute the injection pulse duration Ti. In contrast, if Ti> TiMAX, d. H. if the injection pulse duration Ti exceeds the upper limit TiMAX, the routine goes to step S206 in which the upper limit of the injection pulse duration Ti executed becomes (Ti ← TiMAX), and then the routine goes to step S81.

In Step S81, reference is made to a fuel injection start angle table with the interpolation calculation based on the engine operating condition, based on the engine speed NE and the accelerator pedal position ALPH, by a fuel injection starting angle IJsa based on the upper compression dead center to specify the appropriate cylinder. Subsequently, will in step S82, a fuel injection start timing IJST on Based on the fuel injection starting angle IJsa given, and then the routine ends.

Although in this preferred embodiment, FHPNG = 0, that is, even when the high-pressure fuel system is normal, the abnormal period correction factor KFS with KFS = 1.0 is introduced into the operation equation of the injection pulse duration Ti, while no correction by the abnormal period correction factor KFS is made. However, the present invention should not be limited thereto. When the high pressure fuel system is normal, the specification of the abnormal period correction factor KFS may be omitted, and the abnormal period correction factor KFS may be omitted in the operation equation of the injection pulse duration Ti. That is, when at least the high pressure fuel system is abnormal, the abnormal period correction factor KFS for the correction of the increase in the basic injection pulse duration may be changed depending on the pressure of the low pressure fuel supplied by the low pressure regulator 28 are set to correct the basic injection pulse duration Tp to provide a final injection pulse duration.

THIRD EMBODIMENT

With reference to 25 the third preferred embodiment of the present invention will be described.

In this preferred embodiment, the fuel pressure range covered by the fuel pressure correction factor table becomes the pressure of the low pressure regulator 28 regulated low pressure fuel range he without being limited to the practical fuel pressure range in the embodiments described above.

When the high-pressure fuel system is abnormal, similar to the case where the high-pressure fuel system is normal and when the uniform premixed combustion is selected, a basic fuel injection amount GF suitable for the uniform premixed combustion is represented by Uniform premixed combustion period basic injection amount, and the basic fuel injection amount GF is converted by the basic injection pulse duration table into a basic injection pulse duration Tp provided by the high-pressure regulator 27 regulated controlled fuel pressure PfB corresponds.

Then, based on an actual fuel pressure Pf of the high pressure fuel system received by the fuel pressure sensor 35 is detected, that is, based on the pressure of the injector 13 actually supplied fuel, a fuel pressure correction factor Kp given with reference to the fuel pressure correction factor table, and the basic injection pulse duration Tp is corrected by the fuel pressure correction factor Kp to a final injection pulse duration Ti for the injector 13 pretend.

At this time, the parameter range of the fuel pressure in the fuel pressure correction factor table becomes the pressure of that of the low pressure regulator 28 regulated low-pressure fuel range extended, so that the bypass selector valve 29 is opened by the bypass selector valve control routine when the high-pressure fuel system is abnormal.

So even if that of the low-pressure regulator 28 Regulated low-pressure fuel to the injector 13 is supplied, the basic injection pulse duration Tp, which depends on the by the high-pressure regulating device 27 regulated controlled fuel pressure PfB has been set by the fuel pressure correction factor Kp as a function of the actual fuel pressure of the injector 13 is supplied, are compensated, so that the injection pressure supplied to the injector with the injection pulse duration Ti is compatible.

Consequently can the default operations of the injection pulse duration Ti when the high-pressure fuel system normal and abnormal, quite generally used, so the control system across from the second preferred embodiment is simplified.

In particular, in this preferred embodiment, an in 25 shown fuel injection control routine used in place of the fuel injection control routines of the preferred embodiments described above.

In addition, other routines are the same as in the first preferred embodiment described above, so that their description is omitted. Further, in the fuel injection control routine of FIG 25 the same reference numerals as in the preferred embodiments described above are used for the same steps, and a detailed description is omitted.

Next, the fuel injection control routine according to FIG 25 described.

As in the above-described preferred embodiments, the fuel injection control routine according to FIG 25 each at predetermined times (eg, 10 ms) after system initialization. First, in step S71, the reference to a high pressure fuel system NG flag FHPNG is made. If FHPNG = 0, that is, if the high-pressure fuel system is normal, the routine goes to step S72, where reference is made to a combustion system determination flag FCOMB.

at FCOMB = 0, d. H. if stratified combustion is selected, the routine will increase Step S73, in which the reference to a stratified combustion period basic injection amount table with the interpolation calculation based on the engine operating condition, based on the engine speed NE and the accelerator pedal position ALPH, is done to a basic fuel injection amount GF accordingly to specify a required injection quantity, which for the stratified combustion is suitable and to achieve a predetermined engine power serves.

After the basic fuel injection amount GF is set, the routine goes to step S74 in which the reference to a basic injection pulse duration table is made with the interpolation calculation based on the basic fuel injection amount GF, by a basic injection pulse duration Tp for the injector 13 to be preset, which is used, the basic fuel injection amount GF with a by the high-pressure regulating device 27 to achieve regulated controlled fuel pressure PfB (= 7 MPa).

Subsequently, in step S75, the reference to a fuel pressure correction factor table is made with the interpolation calculation on the basis of that from the fuel pressure sensor 35 detected fuel pressure Pf of the high-pressure fuel system and the basic injection pulse duration Tp to a Fuel pressure correction factor Kp for the compensation of the basic injection pulse duration Tp, which depends on the by the high pressure regulator 27 regulated controlled fuel pressure PfB has been specified, depending on the actual the injector 13 to specify supplied fuel pressure.

In the fuel pressure correction factor table used in this preferred embodiment, the covered fuel pressure range is that of the low pressure regulator 28 regulated pressure of the low pressure fuel range extended without being limited to the practical fuel pressure range of the high pressure fuel system.

At this time, the fuel pressure correction factor table is set as follows. First, the basic injection pulse duration Tp, which is dependent on that by the high pressure regulator 27 regulated controlled fuel pressure PfB (= 7 MPa) has been set for each range defined by the fuel pressure Pf and the basic injection pulse duration Tp, and a coefficient suitable for obtaining the basic fuel injection quantity GF is corrected; is derived beforehand by simulation or experiments.

Then, this coefficient is used as the fuel pressure correction factor Kp, and the fuel pressure correction factor table is set as a table using the fuel pressure Pf and the basic injection pulse duration Tp as parameters. The fuel pressure correction factor table is displayed at a series of addresses in the ROM 52 saved.

The fuel pressure range serving as a parameter in the fuel pressure correction factor table not only covers the practical fuel pressure range of the high-pressure fuel system including the rise process of the fuel pressure Pf at startup, but also covers the pressure of the low-pressure fuel by supplying the low-pressure fuel to the injector 13 by means of the low-pressure regulator 28 so that it is set to be in the range of, for example, 0.2 MPa to 9 MPa in this preferred embodiment.

After the fuel pressure correction factor Kp is set, the routine goes to step S76 where the basic injection pulse duration Tp is multiplied by the fuel pressure correction factor Kp and an air-fuel ratio feedback correction factor KA / F to obtain the fuel pressure correction and the fuel pressure correction factor Kp Perform air / fuel ratio correction to a final injection pulse duration Ti for the injector 13 specify (Ti ← Tp × Kp × KA / F).

Then at step S203, the renewed reference to the high pressure fuel system NG flag is made FHPNG. For FHPNG = 0, d. H. if the high pressure fuel system is normal, the routine goes to step S77, in which the reference to the combustion system determination flag FCOMB.

at FCOMB = 0, d. H. if stratified combustion is selected, the routine will increase Step S78 in which the reference to a fuel injection end timing table with the interpolation calculation based on the engine operating state based on the engine speed NE and the accelerator pedal position ALPH, takes place, to set a fuel injection end time IJEND.

Then at step S79, an ignition timing TADV from the ignition control routine and a fuel injection start timing IJST on the basis the crank pulse θ1 is caused by the reverse operation of the fuel injection end timing IJEND and the injection pulse duration Ti specified from the ignition timing TADV. Then the routine ends.

If on the other hand, FHPNG = 1 in step S71, d. H. if the high pressure fuel system is abnormal, or if FHPNG = 0 in step S71, d. H. if that High-pressure fuel system is normal, and if FCOMB = 1, d. H. if the uniform premixed Combustion chosen is, the routine goes from the respective step to step S80, in which the reference to a uniform premixed combustion period basic fuel injection amount table with the interpolation calculation based on the engine operating condition, based on the engine speed NE and the accelerator pedal position ALPH, is performed to specify a basic fuel injection amount GF, the for the uniform premixed Combustion is appropriate and to obtain a predetermined Output air / fuel ratio is being used.

After the basic fuel injection amount GF is set, the routine goes to step S74 in which the reference to a basic injection pulse duration table is made with the interpolation calculation based on the basic fuel injection amount GF, by a basic injection pulse duration Tp for the injector 13 with one of the high pressure regulator 27 regulated controlled fuel pressure PfB, which serves to obtain the basic fuel injection amount GF.

Then, in step S75, the reference to a fuel pressure correction factor table is made with the interpolation calculation based on that of the Fuel pressure sensor 35 detected fuel pressure Pf of the high-pressure fuel system and the basic injection pulse duration Tp to specify a fuel pressure correction factor Kp.

Then, in step S76, the basic injection pulse duration Tp is multiplied by the fuel pressure correction factor Kp and the air-fuel ratio feedback correction factor KA / F to execute the fuel pressure correction and the air-fuel ratio correction to obtain a final injection pulse duration Ti the injector 13 pretend.

Then at step S203, a renewed reference to the high pressure fuel system NG flag is made FHPNG. For FHPNG = 0, d. H. if the high pressure fuel system is normal, the reference to a combustion system determination flag FCOMB is made in step S77. For FCOMB = 1, d. H. when the uniform premixed combustion chosen is the routine goes from step S77 to step S81.

If on the other hand, in step S203 FHPNG = 1, d. H. if the high pressure fuel system is abnormal, the routine goes to step S205 in which the injection pulse duration Ti is compared with an upper limit TiMAX, previously given was to limit the engine power.

at Ti ≤ TiMAX, d. H. if the injection pulse duration Ti is not greater than the upper limit TiMAX, the upper limit of the injection pulse duration Ti is not executed, and the routine immediately jumps to step S81. In contrast, if Ti> TiMAX, d. H. if the injection pulse duration Ti exceeds the upper limit TiMAX, is the upper limit of the injection pulse duration Ti by the Upper limit TiMAX performed in step S206 (Ti ← TiMAX), and the routine goes to step S81.

In Step S81, reference is made to a fuel injection start angle table with the interpolation calculation based on the engine operating condition, based on the engine speed NE and the accelerator pedal position ALPH, by a fuel injection starting angle IJsa based on the upper compression dead center to specify the appropriate cylinder. Subsequently, will in step S82, a fuel injection start timing IJST on Basis of the fuel injection starting angle IJsa given, and the Routine ends.

As described above, the covered fuel pressure range is not limited to the practical fuel pressure range of the high-pressure fuel system including the rising operation of the fuel pressure Pf at start-up, so that it is extended to the pressure of the low-pressure fuel region by supplying the low-pressure fuel to the injector 13 by means of the low-pressure regulator 28 is obtained when the high-pressure fuel system is abnormal.

In this fuel pressure correction factor table, the fuel pressure correction factor Kp, which is suitable for obtaining the basic fuel injection amount GF by correcting the basic injection pulse duration Tp, is determined by the high-pressure regulator 27 regulated controlled fuel pressure PfB (= 7 MPa) has been preset for each area defined by the fuel pressure Pf and the basic injection pulse duration Tp.

Therefore, the reference to the fuel pressure correction factor table is made on the basis of the fuel pressure Pf of the high pressure fuel system received from the fuel pressure sensor 35 is detected, that is, the actual fuel pressure supplied to the injector, and based on the basic injection pulse duration Tp to set the fuel pressure correction factor Kp, and the basic injection pulse duration Tp, which is dependent on that by the high-pressure regulator 27 regulated fuel pressure PfB has been set is corrected by the fuel pressure correction factor Kp to specify the final injection pulse duration Ti, which is the injection valve opening period of the injector 13 Are defined.

It is thus possible to change the actual fuel injection amount with respect to the required fuel injection amount due to the difference between the injectors 13 to compensate for supplied fuel pressures. Thus, if a high-pressure fuel system receiving a high-pressure fuel is normal, or even if a high-pressure fuel system receiving a low-pressure fuel is abnormal, the injection pulse duration Ti may be set at an appropriate value, so that the actual fuel injection quantity, the one from the injector 13 is injected, coincides with the required injection quantity.

As a result, in both normal and abnormal high-pressure fuel systems, the same specification of the injection pulse width Ti can be used, so that the control system can be simplified. In addition, when a high-pressure fuel system receiving high-pressure fuel is normal, or even when a low-pressure fuel-receiving high-pressure fuel system is abnormal, that of the injector 13 supplied fuel pressure to be compatible with the injection pulse duration Ti, so that an appropriate amount of fuel corresponding to the required fuel injection amount can be injected.

FOURTH EMBODIMENT

With reference to the 26 to 28 The fourth preferred embodiment of the present invention will be described.

In this preferred embodiment, as the high-pressure regulator, a high-pressure electromagnetic regulator 80 used by an ECU 50 can be controlled so that the fuel bypass passage 21d and the bypass selector valve 29 , which are present in the preferred embodiments described above, may be omitted.

Further be for same elements as in the preferred embodiments described above the same reference numbers are used, and these elements become not described again.

The electromagnetic high pressure regulator 80 in this preferred embodiment is of a normally open type, and its valve position becomes one of the ECU depending on the duty DUTY 50 output driver signal controlled. When the duty cycle DUTY of the ECU 50 output driver signal 00H (0%) is the regulator 80 fully open, and its valve position decreases with increasing duty DUTY. When the duty cycle is DUTY FFH (100%), the regulator is 80 completely closed.

As 26 shows is the downstream side of the high pressure electromagnetic regulation device 80 with a fuel return passage between a low pressure fuel passage 21a downstream from a feed pump 24 and upstream of a feed pump 24 and the upstream side of the low-pressure regulator 28 connected as a low-pressure fuel system.

Besides, how is 27 shows the high pressure electromagnetic regulation 80 with the output port of the I / O interface 56 the ECU 50 via a driver circuit 58 connected.

The ECU 50 leads an in 28 shown electromagnetic high-pressure regulator control routine. When FHPNG = 0, that is, when the high pressure fuel system is normal, a duty ratio DUTY of a drive signal to the electromagnetic high pressure regulator becomes 80 depending on the comparison results of a predetermined target controlled fuel pressure PfB (eg, PfB = 7 MPa in this preferred embodiment) with a fuel pressure Pf of the high pressure fuel system received from a fuel pressure sensor 35 is detected, and the feedback control for the high-pressure electromagnetic regulating device 80 is executed so that the fuel pressure Pf of the high-pressure fuel system approaches the controlled fuel pressure PfB.

On the other hand, when FHPNG = 1, that is, when the high-pressure fuel system is abnormal, a controlled variable for fully opening the high-pressure electromagnetic regulator becomes 80 that is, the duty ratio DUTY of the drive signal to the electromagnetic high-pressure regulator 80 is specified as DUTY = OOH.

Thus, the electromagnetic high pressure regulator becomes 80 fully opened to make the connection between the high-pressure fuel system and the low-pressure fuel system, so that one of the supply pump 24 supplied low pressure fuel passing through the low pressure regulator 28 is to be regulated to a predetermined fuel pressure, is fed directly to the high-pressure fuel system to the injector 13 to be fed.

In this preferred embodiment, the ECU 50 also a function as a high-pressure regulator control device according to the present invention.

Further, other routines in the above-described preferred embodiments are adopted in an appropriate manner, and their descriptions are omitted. In addition, in this preferred embodiment, the bypass selector valve 29 not provided so that the bypass selector valve control routine of 5 in the first embodiment described above is not required.

Hereinafter, the electromagnetic high-pressure regulator control routine of FIG 28 described.

In the 28 The electromagnetic high-pressure regulator control routine shown is executed every predetermined time (eg, 10 ms) after the system initialization. First, in step S301, the reference to a high pressure fuel system NG flag FHPNG is made. If FHPNG = 0, that is, if the high-pressure fuel system is normal, the routine goes to step S302.

In step S302, the reference is made to a normal control transition flag F2 indicating the transition to a normal control (feedback control). This normal control transition flag F2 is set when the fuel pressure Pf of the high-pressure fuel system reaches predetermined fuel pressure after starting the engine so that its initial value F2 = 0.

If F2 = 0, the routine goes to step S303, where reference is made to an initialization completion flag 1 which is set when the initialization of the duty ratio DUTY to the high pressure electromagnetic regulator 80 finished. At F1 = 0, that is, when this routine is first executed when the high-pressure fuel system is normal, the routine goes to step S304 in which the duty ratio DUTY is set to "FFH" to fully close the high-pressure electromagnetic regulator 80 is specified (DUTY ← FFH).

Subsequently, will in step S304, the initialization completion flag 1 by the End of initialization set (F1 ← 1). Then, in step S306 the duty cycle DUTY predetermined in step S304, and the routine ends.

As a result, the high-pressure electromagnetic regulation device 80 a drive signal based on the duty DUTY = FFH output, so that the electromagnetic high pressure regulator 80 is completely closed, to prevent fuel from the high pressure electromagnetic regulation device 80 exit.

After completion of the initialization F1 = 1, the routine proceeds from step S303 to 5307 in which the fuel pressure sensor 35 detected fuel pressure Pf of the high-pressure fuel system is compared with a preset pressure PH.

The preset pressure PH determines whether the fuel pressure Pf of the high-pressure fuel system, ie the pressure of the injector 13 supplied fuel substantially reaches the controlled target fuel pressure PfB. In this preferred embodiment, the preset pressure PH is set so that PH = 67 MPa.

at Pf ≤ PH, d. H. when the fuel pressure Pf of the high-pressure fuel system has not yet reached the controlled target fuel pressure the routine immediately. At Pf> PH, d. H. when the fuel pressure Pf of the high pressure fuel system the controlled target fuel pressure substantially goes the routine goes to step S308 in which the normal control transition flag F2, the transition to the normal control (feedback control) is set (F2 ← 1), and the routine ends.

That is, after driving the high pressure pump 25 has been started by starting the engine is the high pressure electromagnetic regulation device 80 fully closed until the fuel pressure Pf of the high pressure fuel system reaches the predetermined fuel pressure, to the open control of the high pressure electromagnetic regulator 80 so as to prevent fuel from leaking from the high-pressure electromagnetic regulator to raise the fuel pressure Pf of the high-pressure fuel system early to the target controlled fuel pressure PfB.

Thereafter, the routine goes from step S302 to S309 because the normal control transition flag F2 is set. In the steps 309 to 313 becomes a duty DUTY of a drive signal to the electromagnetic high-pressure regulator 80 in response to the comparison results of the target controlled fuel pressure PfB (= 7 MPa) with the fuel pressure Pf of the high pressure fuel system received from the fuel pressure sensor 35 is detected, and the feedback control of the high-pressure electromagnetic regulating device 80 is performed so that the fuel pressure Pf of the high-pressure fuel system is approximated to the controlled fuel pressure PfB.

That is, in step S309, that of the fuel pressure sensor 35 is subtracted from the preset target controlled fuel pressure PfB to derive a difference ΔP between the controlled fuel pressure PfB and the fuel pressure Pf (ΔP ← PfB - Pf). Subsequently, in step S310, a proportional constant KPF of a proportional integral control (PI control) is multiplied by the difference ΔP to obtain a proportional component feedback value (P ← KPF × ΔP).

Further at step S311, the last integral component feedback value IOLD is added to a value obtained by multiplying an integral constant KI of the proportional-integral control with the difference .DELTA.P obtained is to derive a new integral component feedback value I (I ← IOLD + KI × ΔP).

Then, in step S312, the last integral component feedback value IOLD is updated with the currently derived integral component feedback value I to be ready for the next routine. Subsequently, in step S313, the proportional component feedback value P and the integral component feedback value I are added to a basic duty ratio DB given in response to the controlled fuel pressure PfB to obtain a duty DUTY which is the controlled variable for the electromagnetic high pressure -Reguliereinrichtung 80 Are defined (DUTY ← DB + P + I).

Then the routine goes to step S306 in which the one calculated in step S313 DUTY is set, and the routine ends.

As a result, the ECU 50 to the high pressure electromagnetic regulator 80 a drive signal based on the duty DUTY output, and the valve position of the high pressure electromagnetic regulator 80 is controlled in response to the duty DUTY to perform the feedback control, so that the fuel pressure Pf of the high-pressure fuel system approaches the controlled fuel pressure PfB.

So if FHPNG = 0, ie if the high-pressure fuel system is normal, the injector will 13 a high pressure fuel supplied by the high pressure pump 25 is pressurized to from the high pressure electromagnetic regulating device 80 to be regulated to a predetermined controlled fuel pressure.

On the other hand, if FHPNG = 1 in step S301, that is, if the high-pressure fuel system is abnormal, the routine goes to step S314, in which the duty ratio DUTY, which is the controlled variable high-pressure regulator variable 80 defined with "00H" to fully open the high pressure electromagnetic regulator 80 is predetermined (DUTY ← 00H).

Then at step S315 and S316, the initialization completion flag F1 and the normal control transition flag F2 reset (F1 ← 0, F2 ← 0). Then, the routine goes to step S306 in which the duty ratio DUTY (= 00H) set in step S314 is set, and the routine ends.

As a result, the high-pressure electromagnetic regulation device 80 a drive signal based on the duty DUTY = 00H output to the high-pressure electromagnetic regulator 80 completely open.

Therefore, when the high pressure fuel system is abnormal, the high pressure electromagnetic regulator becomes 80 fully opened to make the connection between the high-pressure fuel system and the low-pressure fuel system, so that of the feed pump 24 supplied low-pressure fuel passing through the low-pressure regulator 28 to be regulated to a predetermined fuel can be supplied directly to the high-pressure fuel system to be supplied to the injector, as well as in the first embodiment described above, regardless of the high-pressure fuel.

Therefore, the electromagnetic high-pressure regulator 80 the same function as the bypass selector valve 29 in the first preferred embodiment described above, and it is possible to use the bypass selector valve 29 and the fuel bypass passage 21d not to be used, so that the number of parts of the fuel supply system can be reduced to simplify the construction of the fuel supply system.

Further the present invention should not be limited to those described embodiments limited be. For example, the accelerator pedal position ALPH has been described merely as an example of the engine load in the preferred embodiments described above used, but instead of the accelerator pedal position ALPH can also be a Throttle position, an intake air amount, an intake pipe pressure downstream a throttle or an intake air amount used per intake stroke become.

Further be in the preferred embodiments described above the ignition timing and the fuel injection timing is controlled by the timing system, however, the present invention should not be so limited; for controlling the ignition timing and the fuel injection timing may also be the control angle control system dependent on be applied by the angle.

The Presently preferred embodiments of present invention are shown and described above; It is understood, however, that the present Revelation serves only as an illustration and that numerous Modifications and changes can be made without departing from the scope of the invention as defined in the appended claims is to deviate.

Claims (13)

Control system for controlling a high pressure fuel system for an engine ( 1 ) with fuel injection in the cylinder, wherein a low-pressure fuel from a low-pressure pump ( 24 ) is supplied by a low pressure regulator ( 28 ) is regulated to a predetermined fuel pressure to a high pressure pump ( 25 ), the pressure of the fuel from the high pressure pump ( 25 ) is increased to an injector ( 13 ) a high-pressure fuel for injecting the high-pressure fuel directly into a cylinder ( 12 ), wherein a high-pressure regulating device ( 27 ) and Diagnostic means are provided for determining that the high pressure fuel system is abnormal when the fuel pressure is abnormal, characterized in that the diagnostic means are adapted to measure the fuel pressure behavior of the high pressure fuel system and the relationship between an air / fuel pressure. Fuel ratio and injection pulse duration for the injector ( 13 ) and that the diagnostic devices determine that the high pressure fuel system is abnormal and provide information about that abnormal condition when at least one of the conditions that the fuel pressure is abnormal and the air / fuel ratio is incompatible with the fuel injection pulse , is satisfied; and that ignition timing control means are provided for determining, on the basis of the operating condition of the engine ( 1 ) to specify an ignition timing suitable for uniform premixed combustion when the high pressure fuel system is normal and when uniform premixed combustion is selected or when the high pressure fuel system is abnormal. The system of claim 1, further comprising: - an open / close valve device (10); 29 ) located in a fuel bypass channel ( 21d ) is provided, which is provided to the high-pressure regulating device ( 27 ) to connect between a high pressure fuel system and a low pressure fuel system; - open / close valve control devices ( 29 . 30 ) for closing the open / close valve device ( 29 ), when the high pressure fuel system is normal, and to open the open / close valve device (FIG. 29 ) when the high pressure fuel system is abnormal; and fuel injection control means for setting an injection pulse duration which is a fuel injection quantity for the injector (FIG. 13 ) on the basis of the engine operating condition in dependence on that of the high pressure regulator ( 27 ) controlled fuel pressure when the high-pressure fuel system is normal, and fuel injection control means for setting the injection pulse duration based on the engine operating condition in response to the low-pressure regulator ( 28 ) regulated pressure of a low pressure fuel when the high pressure fuel system is abnormal. System according to claim 1, - wherein the high-pressure regulating device comprises a high-pressure electromagnetic regulation device ( 80 ), whose downstream side is connected to the low-pressure fuel system, wherein the injector ( 13 ) sets an injection timing and an injection amount of the fuel based on an engine operating condition, and injects the fuel injection amount directly into the cylinder ( 12 ) injects; and wherein the system further comprises: high pressure regulator control means for providing a controlled variable to the high pressure electromagnetic regulation means ( 80 ), so that a predetermined controlled fuel pressure is obtained when the high pressure fuel system is normal, the high pressure regulator controllers being arranged to provide a controlled variable such that the high pressure electromagnetic regulator (FIG. 80 ) is fully opened when the high pressure fuel system is abnormal; and fuel injection control means for setting an injection pulse duration which is a fuel injection quantity for the injector (FIG. 13 ) on the basis of the engine operating condition in dependence on that of the high-pressure electromagnetic regulation device ( 80 ) controlled controlled fuel pressure when the high-pressure fuel system is normal, wherein the fuel injection control means are adapted to an injection pulse duration on the basis of the engine operating condition in dependence on that of the low-pressure regulator ( 28 ) provide regulated pressure of low pressure fuel when the high pressure fuel system is abnormal. The system of claim 2 or 3, further comprising: a fuel pressure correction factor table that uses a fuel pressure in a practical use range of the high-pressure fuel system as a parameter to include therein a fuel pressure correction factor for correcting the change of the fuel injection amount based on To store fuel pressure; and an abnormal-period injection pulse duration table that uses an engine speed and an engine load as parameters to store therein an injection pulse duration that is capable of controlling a required fuel injection amount with that of the low-pressure regulator (US Pat. 28 ) to obtain regulated pressure of a low-pressure fuel; Wherein, when the high pressure fuel system is normal, the fuel injection controller sets a basic fuel injection amount based on the engine operating condition to provide a basic injection pulse duration that is used to apply the basic fuel injection amount to one of the high pressure regulator ( 27 ) or the high-pressure electromagnetic regulation device ( 80 ), and the one valve opening basic period for the injector (FIG. 13 ) based on the basic fuel injection amount, and wherein the fuel injection control means is responsive to the fuel pressure correction factor table on the Based on the fuel pressure of the high pressure fuel system, to set a fuel pressure correction factor to correct the basic injection pulse duration by the fuel pressure correction factor to provide a final injection pulse duration for the injector; and wherein, when the high pressure fuel system is abnormal, the fuel injection controllers refer to the abnormal period injection pulse duration table based on the engine speed and the engine load to obtain a final injection pulse duration for the injector ( 13 ) pretend. The system of claim 2 or 3, further comprising: a fuel pressure correction factor table that uses a fuel pressure in a practical use range of the high-pressure fuel system as a parameter to therein a fuel pressure correction factor for correcting the change of the fuel injection amount on the basis of Fuel pressure to store, - wherein the fuel injection control means predetermine a basic fuel injection amount based on the engine operating condition to specify a basic injection pulse duration, which is used, the basic fuel injection quantity with one of the high pressure regulator ( 27 ) or the high-pressure electromagnetic regulation device ( 80 ), and the one valve opening basic period for the injector (FIG. 13 ) based on the basic fuel injection amount, and wherein the fuel injection control means refer to the fuel pressure correction factor table based on the fuel pressure of the high pressure fuel system to set a fuel pressure correction factor, wherein the fuel injection control means is an abnormal period Correction factor for the correction to the basic injection pulse duration in dependence on that of the low-pressure regulating device ( 28 ) to increase regulated pressure of a low pressure fuel when at least the high pressure fuel system is abnormal; and wherein the fuel injection control means corrects the basic injection pulse duration by the fuel pressure correction factor and the abnormal period correction factor to obtain a final injection pulse duration for the fuel injection Injectors ( 13 ) pretend. A system according to claim 2 or 3, further comprising: - a fuel pressure correction factor table corresponding to that of the low pressure regulator ( 28 ) uses regulated pressure of a low-pressure fuel and a fuel pressure in a practical use range of the high-pressure fuel system as parameters to store therein a fuel pressure correction factor for correcting the change of the fuel injection amount on the basis of the fuel pressure, wherein the fuel injection control means is a basic Fuel injection amount based on the engine operating condition to provide a basic injection pulse duration that is used to apply the basic fuel injection amount to one of the high pressure regulator ( 27 ) or the high-pressure electromagnetic regulation device ( 80 ), and the one valve opening basic period for the injector (FIG. 13 ) based on the basic fuel injection amount, and wherein the fuel injection control means refers to the fuel pressure correction factor table based on the fuel pressure of the high pressure fuel system to set a fuel pressure correction factor to the basic injection pulse duration by the fuel pressure correction factor to correct to give a final injection pulse duration for the injector. The system of claim 1, wherein during low engine speeds at low loads, a late-injection-based stratified combustion is selected to be based on the operating condition of the engine (1). 1 ) set a fuel injection amount, a fuel injection timing, and an ignition timing suitable for the stratified combustion, whereas during high engine speeds with high loads, uniform premixed combustion based on an early injection is selected to determine a fuel injection amount, a fuel injection timing, and on the basis of the engine operating condition specify an ignition timing suitable for the uniform premixed combustion, wherein the fuel injection quantity from the injector ( 13 ) directly into a cylinder ( 12 ) to inject the injected fuel through a spark plug ( 13 ) at ignition timing to achieve stratified combustion or uniform premixed combustion, the system further comprising: - an open / close valve device ( 29 ) located in a fuel bypass channel ( 21d ) is provided, which is provided to the high-pressure regulating device ( 27 ) to connect between a high pressure fuel system and a low pressure fuel system; - open / close valve control devices ( 29 . 30 ) for closing the open / close valve device ( 29 ), when the high-pressure fuel system is normal, and to open the open / close valve device ( 29 ) when the high pressure fuel system is abnormal; A combustion system selector to based on the engine operating condition, the stratified combustion based on the late injection during low engine speeds with low loads and the uniform premixed combustion based on the early injection during high engine speeds with high loads; - Fuel injection control means for setting an injection pulse duration for the injector ( 13 ) defining a fuel injection amount suitable for the stratified combustion based on the operating state of the engine ( 1 ) in dependence on that of the high pressure regulator ( 27 ) regulated controlled fuel pressure and for setting a fuel injection timing in a compression stroke of a cylinder ( 12 ) to which an injection is to be made when the high-pressure fuel system is normal and when the stratified combustion is selected, the fuel injection controllers being based on the operating state of the engine ( 1 ) in dependence on that of the high pressure regulator ( 27 ) regulated controlled fuel pressure an injection pulse duration for the injector ( 13 ), which is suitable for the uniform premixed combustion, and a fuel injection timing at the end of an exhaust stroke or during an intake stroke of a cylinder ( 12 ) to be injected, when the high-pressure fuel system is normal and when the uniform premixed combustion is selected, and wherein the fuel injection controllers are based on the operating state of the engine ( 1 ) in dependence on that of the low-pressure regulator ( 28 ) predetermined pressure of a low-pressure fuel set an injection pulse duration, which is suitable for the uniform premixed combustion, and a fuel injection timing, which is suitable for the uniform premixed combustion when the high-pressure fuel system is abnormal; and wherein the spark timing control means sets, based on the engine operating condition, an ignition timing suitable for stratified combustion, when the high pressure fuel system is normal, and when the stratified combustion is selected. The system of claim 1, wherein during low engine speeds at low loads, a late-injection stratified combustion is selected to be based on the operating condition of the engine (1). 1 ) set a fuel injection amount, a fuel injection timing, and an ignition timing suitable for stratified combustion, whereas during high engine speeds with high loads, uniform premixed combustion based on an early injection is selected to set a fuel injection amount, a fuel injection amount based on the engine operating condition Preset fuel injection timing and an ignition timing, which are suitable for the uniform premixed combustion, wherein the fuel injection amount of the injector ( 13 ) directly into a cylinder ( 12 ) is injected to ignite the injected fuel through a spark plug at the ignition timing to achieve the stratified combustion or the uniform premixed combustion, the high-pressure regulator comprising a high-pressure electromagnetic regulator (US Pat. 80 ), whose downstream side is connected to the low-pressure fuel system, wherein the injector ( 13 ) sets a fuel injection timing and a fuel injection amount based on the engine operating condition, and directly injects the injection amount of fuel into the cylinder ( 12 ) injects; and wherein the system further comprises: high pressure regulator control means for providing a controlled variable to the high pressure electromagnetic regulation means ( 80 ), so that a predetermined controlled fuel pressure is obtained when the high-pressure fuel system is normal, the high-pressure regulator control means being adapted to set the controlled variable so that the high-pressure electromagnetic control means ( 80 ) is fully opened when the high pressure fuel system is abnormal; Combustion system selectors to select, based on the engine operating condition, the stratified combustion based on the late injection during low engine low-speed engine speeds and the uniform premixed combustion based on the early injection during high-load high engine speeds; - Fuel injection control means for setting an injection pulse duration for the injector ( 13 ) defining a fuel injection amount suitable for the stratified combustion, on the basis of the engine operating condition in response to that of the high-pressure electromagnetic regulator ( 80 ) regulated controlled fuel pressure and for setting a fuel injection timing in a compression stroke of a cylinder ( 12 ) to which injection is to be made when the high pressure fuel system is normal and the stratified combustion is selected, the fuel injection controllers being based on the engine operating condition in response to the high pressure electromagnetic regulation (FIG. 80 ) regulated controlled fuel pressure an injection pulse duration for the injector ( 13 ), which is suitable for the uniform premixed combustion, and a fuel injection timing at the end of a Auslaßhubs or a suction stroke of the cylinder ( 12 ), in which an injection is to occur, pretend when the high-pressure force fuel system is normal and when the uniform premixed combustion is selected, and the fuel injection control devices based on the engine operating condition in response to that of the low-pressure regulator ( 28 ) predetermined pressure of a low-pressure fuel set an injection pulse duration, which is suitable for the uniform premixed combustion, and a fuel injection timing, which is suitable for the uniform premixed combustion when the high-pressure fuel system is abnormal; and wherein the spark timing control means sets, based on the engine operating condition, an ignition timing suitable for stratified combustion, when the high pressure fuel system is normal, and when the stratified combustion is selected. The system of claim 7 or 8, further comprising: a fuel pressure correction factor table that uses a fuel pressure in a practical use range of the high-pressure fuel system as a parameter to therein a fuel pressure correction factor for correcting the change of the fuel injection amount based on To store fuel pressure; and an abnormal-period injection pulse duration table which uses an engine speed and an engine load as parameters to store therein an injection pulse duration capable of obtaining a required fuel injection amount for uniform premixed combustion with that of the low-pressure regulator ( 28 ) regulated pressure of a low-pressure fuel is suitable; Wherein the fuel injection controllers determine a basic fuel injection amount that is appropriate for the stratified combustion when the high pressure fuel system is normal and when the stratified combustion is selected, and based on the engine operating condition based on the engine operating condition, specify a basic fuel injection amount based on the engine operating condition, suitable for uniform premixed combustion when the high pressure fuel system is normal and when uniform premixed combustion is selected; Wherein the fuel injection control devices specify a basic injection pulse duration that is used to adjust the basic fuel injection quantity to one of the high-pressure regulating device ( 27 ) or the high-pressure electromagnetic regulation device ( 80 ), and the one valve opening basic period for the injector (FIG. 13 ) based on the basic fuel injection amount, and the fuel injection control devices refer to the fuel pressure correction factor map based on the fuel pressure of the high pressure fuel system to set a fuel pressure correction factor to increase the basic injection pulse duration by the fuel pressure correction factor to determine a final injection pulse duration for the injector ( 13 ) pretend; and wherein the fuel injection controllers refer to the abnormal-period injection pulse duration map based on the engine speed and the engine load to obtain a final injection pulse duration for the injector ( 13 ) when the high pressure fuel system is abnormal. The system of claim 7 or 8, further comprising: a fuel pressure correction factor table that uses a fuel pressure in a practical use range of the high-pressure fuel system as a parameter to therein a fuel pressure correction factor for correcting the change of the fuel injection amount based on To store fuel pressure; Wherein the fuel injection controllers determine a basic fuel injection amount that is appropriate for the stratified combustion when the high pressure fuel system is normal and when the stratified combustion is selected, and based on the engine operating condition based on the engine operating condition, specify a basic fuel injection amount based on the engine operating condition, suitable for the uniform premixed combustion, when the high pressure fuel system is normal and when the uniform premixed combustion is selected or when the high pressure fuel system is abnormal, - the fuel injection controllers provide a basic injection pulse duration that is used to the basic fuel injection amount with one of the high pressure regulator ( 27 ) or the high-pressure electromagnetic regulation device ( 80 ), and the one valve opening basic period for the injector (FIG. 13 ) based on the basic fuel injection amount, the fuel injection controllers referring to the fuel pressure correction factor map based on the fuel pressure of the high pressure fuel system to provide a fuel pressure correction factor; - wherein the fuel injection control means specify an abnormal period correction factor for the correction to the basic injection pulse duration in dependence on that of the low pressure regulator ( 28 ) to increase regulated pressure of a low pressure fuel when at least the high pressure fuel system is abnormal; and wherein the fuel injection control means corrects the basic injection pulse duration by the fuel pressure correction factor and the abnormal period correction factor to obtain a final injection pulse duration for the injector (FIG. 13 ) vorzu give. A system according to claim 7 or 8, further comprising: - a fuel pressure correction factor table corresponding to that of the low pressure regulator ( 28 ) uses regulated pressure of a low pressure fuel and a fuel pressure in a practical use range of the high pressure fuel system as parameters to store therein a fuel pressure correction factor for correcting the change of the fuel injection amount based on the fuel pressure; Wherein the fuel injection controllers determine a basic fuel injection amount that is appropriate for the stratified combustion when the high pressure fuel system is normal and when the stratified combustion is selected, and based on the engine operating condition based on the engine operating condition, specify a basic fuel injection amount based on the engine operating condition, suitable for the uniform premixed combustion when the high pressure fuel system is normal and when the uniform premixed combustion is selected or when the high pressure fuel system is abnormal; Wherein the fuel injection control devices specify a basic injection pulse duration that is used to adjust the basic fuel injection quantity to one of the high-pressure regulating device ( 27 ) or the high-pressure electromagnetic regulation device ( 80 ), and based on the basic fuel injection amount, a valve opening basic period for the injector (Fig. 13 ), and the fuel injection control means refer to the fuel pressure correction factor table on the basis of the fuel pressure of the high pressure fuel system to set a fuel pressure correction factor to correct the basic injection pulse duration by the fuel pressure correction factor to a final injection pulse duration the injector ( 13 ) pretend. A system according to any one of claims 2 to 11, wherein the fuel injection control means comprises Make upper limit of the injection pulse duration, the predetermined will if the high pressure fuel system is abnormal. A system according to any one of claims 1 to 12, wherein the diagnostic devices determine that High-pressure fuel system is abnormal when at least one of met the conditions is that the Fuel pressure of the high-pressure fuel system a predetermined Pressure is not reached even if a predetermined period of time After starting the engine has passed that the fuel pressure of the high-pressure fuel system after starting the engine, not within a normal fuel pressure range is, and that the Injection pulse duration continues, a predetermined value for a exceed predetermined period of time at a lean air / fuel ratio.